<PAGE>
 
                                                                    EXHIBIT 10.3


[LOGO OF SILICON VALLEY BANK]


                          LOAN AND SECURITY AGREEMENT


BORROWER:  NETVANTAGE, INC.

ADDRESS:   201 CONTINENTAL BOULEVARD, SUITE 201
           EL SEGUNDO, CALIFORNIA  90245

DATE:      JULY 15, 1996
                --

THIS LOAN AND SECURITY AGREEMENT is entered into on the above date between
SILICON VALLEY BANK ("Silicon"), whose address is 3003 Tasman Drive, Santa
Clara, California 95054 and the borrower named above (the "Borrower"), whose
chief executive office is located at the above address ("Borrower's Address").

1.  LOANS.

  1.1  LOANS.  Silicon, in its reasonable discretion, will make loans to the
Borrower (the "Loans") in amounts determined by Silicon in its reasonable
discretion up to the amount (the "Credit Limit") shown on the Schedule to this
Agreement (the "Schedule"), provided no Event of Default and no event which,
with notice or passage of time or both, would constitute an Event of Default has
occurred.  The Borrower is responsible for monitoring the total amount of Loans
and other Obligations outstanding from time to time, and Borrower shall not
permit the same, at any time, to exceed the Credit Limit.  If at any time the
total of all outstanding Loans and all other Obligations exceeds the Credit
Limit, the Borrower shall immediately pay the amount of the excess to Silicon,
without notice or demand.

  1.2  INTEREST.  All Loans and all other monetary Obligations shall bear
interest at the rate shown on the Schedule hereto.  Interest shall be payable
monthly, on the due date shown on the monthly billing from Silicon to the
Borrower. Silicon may, in its discretion, charge interest to Borrower's deposit
accounts maintained with Silicon.

  1.3  FEES.  The Borrower shall pay to Silicon a loan origination fee in the
amount shown on the Schedule hereto concurrently herewith.  This fee is in
addition to all interest and other sums payable to Silicon and is not
refundable.

  1.4  LETTERS OF CREDIT.  Silicon, in its reasonable discretion, will, from
time to time during the term of this Agreement, on the request of the Borrower,
issue letters of credit for the account of the Borrower ("Letters of Credit"),
in an aggregate amount at any one time outstanding not to exceed the Letter of
Credit Sublimit shown on the Schedule, provided that, on the date the Letters of
Credit are to be issued, Borrower has available to it Loans in an amount equal
to or greater than the face amount of the Letters of Credit to be issued.
Letters of Credit shall be in form and substance acceptable to Silicon in its
sole discretion, shall be payable in United States dollars and shall have an
expiry date no later than the Maturity Date *.  Prior to the issuance of any
Letters of Credit, Borrower shall execute and deliver to Silicon applications
for letters of credit, and letter of credit agreements on Silicon's standard
forms, and such other documentation as Silicon shall specify (the "Letter of
Credit Documentation"). Fees for Letters of Credit shall be as provided in the
Letter of Credit Documentation. Borrower shall indemnify, defend and hold
Silicon harmless from any loss, cost, expense or liability, including without
limitation reasonable attorneys fees, arising out of or relating to Letters of
Credit. The Credit Limit and the Loans available to Borrower under this
Agreement shall be reduced by the face amount of Letters of Credit from time to
time outstanding.

  * PROVIDED THAT LETTERS OF CREDIT MAY HAVE A MATURITY DATE UP TO TWELVE MONTHS
BEYOND THE MATURITY DATE IN EFFECT FROM TIME TO TIME, PROVIDED THAT IF ON THE
MATURITY DATE, OR ON ANY EARLIER EFFECTIVE DATE OF TERMINATION, THERE ARE ANY
OUTSTANDING LETTERS OF CREDIT ISSUED BY SILICON OR ISSUED BY ANOTHER INSTITUTION
BASED UPON AN APPLICATION, GUARANTEE, INDEMNITY OR SIMILAR AGREEMENT ON THE PART
OF SILICON, THEN ON SUCH DATE BORROWER SHALL PROVIDE TO SILICON CASH COLLATERAL
IN AN AMOUNT EQUAL TO THE FACE AMOUNT OF ALL SUCH LETTERS OF CREDIT PLUS ALL
INTEREST, FEES AND COST DUE OR TO BECOME DUE IN CONNECTION THEREWITH, TO SECURE
ALL OF THE OBLIGATIONS RELATING TO SAID LETTERS OF CREDIT, PURSUANT TO SILICON'S
THEN STANDARD FORM CASH PLEDGE AGREEMENT.


NOTE TO EDGAR VERSION:  Deleted language is indicated by brackets, not 
                        strike-throughs.

                                      -1-
<PAGE>
 
Silicon Valley Bank                                  Loan and Security Agreement
--------------------------------------------------------------------------------

2.  GRANT OF SECURITY INTEREST.

  2.1  OBLIGATIONS.  The term "Obligations" as used in this Agreement means the
following:  the obligation to pay all Loans and all interest thereon when due,
and to pay and perform when due all other present and future indebtedness,
liabilities, obligations, guarantees, covenants, agreements, warranties and
representations of the Borrower to Silicon, whether joint or several, monetary
or non-monetary, and whether created pursuant to this Agreement or any other
present or future agreement or otherwise.  Silicon may, in its discretion,
require that Borrower pay monetary Obligations in cash to Silicon, or charge
them to Borrower's Loan account, in which event they will bear interest at the
same rate applicable to the Loans.  Silicon may also, in its discretion, charge
any monetary Obligations to Borrower's deposit accounts maintained with Silicon.
Silicon will notify the Borrower of any such charges to Borrower's deposit
accounts.  Such charges shall not be deemed to be a setoff for any purpose.

  2.2  COLLATERAL.  As security for all Obligations, the Borrower hereby grants
Silicon a continuing security interest in all of the Borrower's interest in the
types of property described below, whether now owned or hereafter acquired, and
wherever located (collectively, the "Collateral"):  (a) All accounts, contract
rights, chattel paper, letters of credit, documents, securities, money, and
instruments, and all other obligations now or in the future owing to the
Borrower; (b) All inventory, goods, merchandise, materials, raw materials, work
in process, finished goods, farm products, advertising, packaging and shipping
materials, supplies, and all other tangible personal property which is held for
sale or lease or furnished under contracts of service or consumed in the
Borrower's business, and all warehouse receipts and other documents; and (c) All
equipment, including without limitation all machinery, fixtures, trade fixtures,
vehicles, furnishings, furniture, materials, tools, machine tools, office
equipment, computers and peripheral devices, appliances, apparatus, parts, dies,
and jigs; (d) All general intangibles including, but not limited to, deposit
accounts, goodwill, names, trade names, trademarks and the goodwill of the
business symbolized thereby, trade secrets, drawings, blueprints, customer
lists, patents, patent applications, copyrights, security deposits, loan
commitment fees, federal, state and local tax refunds and claims, all rights in
all litigation presently or hereafter pending for any cause or claim (whether in
contract, tort or otherwise), and all judgments now or hereafter arising
therefrom, all claims of Borrower against Silicon, all rights to purchase or
sell real or personal property, all rights as a licensor or licensee of any
kind, all royalties, licenses, processes, telephone numbers, proprietary
information, purchase orders, and all insurance policies and claims (including
without limitation credit, liability, property and other insurance), and all
other rights, privileges and franchises of every kind; (e) All books and
records, whether stored on computers or otherwise maintained; and (f) All
substitutions, additions and accessions to any of the foregoing, and all
products, proceeds and insurance proceeds of the foregoing, and all guaranties
of and security for the foregoing; and all books and records relating to any of
the foregoing.  Silicon's security interest in any present or future technology
(including patents, trade secrets, and other technology) shall be subject to any
licenses or rights now or in the future granted by the Borrower to any third
parties in the ordinary course of Borrower's business; provided that if the
Borrower proposes to sell, license or grant any other rights with respect to any
technology in a transaction that, in substance, conveys a major part of the
economic value of that technology, Silicon shall first be requested to release
its security interest in the same, and Silicon may withhold such release in its
discretion *.

  * PROVIDED THAT IT IS UNDERSTOOD THAT SILICON WILL NOT WITHHOLD ITS CONSENT TO
    --------                                                                    
A TRANSACTION THAT PERMITS A THIRD PARTY TO COMPLETE MANUFACTURING OF A PRODUCT
INVOLVING SUCH TECHNOLOGY ONLY, WITHOUT THE GRANT OF ANY OTHER RIGHTS TO SUCH
PARTY IN SUCH TECHNOLOGY ARISING IN CONNECTION THEREWITH

3.  REPRESENTATIONS, WARRANTIES AND COVENANTS OF THE BORROWER.

  The Borrower represents and warrants to Silicon as follows, and the Borrower
covenants that the following representations will continue to be true, and that
the Borrower will comply with all of the following covenants:

  3.1  CORPORATE EXISTENCE AND AUTHORITY.  The Borrower, if a corporation, is
and will continue to be, duly authorized, validly existing and in good standing
under the laws of the jurisdiction of its incorporation.  The Borrower is and
will continue to be qualified and licensed to do business in all jurisdictions
in which any failure to do so would have a material adverse effect on the
Borrower.  The execution, delivery and performance by the Borrower of this
Agreement, and all other documents contemplated hereby have been duly and
validly authorized, are enforceable against the Borrower in accordance with
their terms, and do not violate any law or any provision of, and are not grounds
for acceleration under, any agreement or instrument which is binding upon the
Borrower.  Borrower has no subsidiaries except as set forth on the Schedule.

  3.2  NAME; TRADE NAMES AND STYLES.  The name of the Borrower set forth in the
heading to this Agreement is its correct name.  Listed on the Schedule hereto
are all prior names of the Borrower and all of Borrower's present and prior
trade names.  The Borrower shall give Silicon 15 days' prior written notice
before changing its name or doing business under any other name.  The Borrower
has complied, and will in the future comply, with all laws relating to the
conduct of business under a fictitious business name.

  3.3  PLACE OF BUSINESS; LOCATION OF COLLATERAL.  The address set forth in the
heading to this Agreement is the Borrower's chief executive office.  In
addition, the Borrower has places of business and Collateral is located only at
the locations set forth on the Schedule to this Agreement.  The Borrower will
give Silicon at least 15 days prior written notice before changing its chief
executive office or locating the Collateral at any other location.

                                      -2-
<PAGE>
 
Silicon Valley Bank                                  Loan and Security Agreement
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  3.4  TITLE TO COLLATERAL; PERMITTED LIENS.  The Borrower is now, and will at
all times in the future be, the sole owner of all the Collateral, except for
items of equipment which are leased by the Borrower *.  The Collateral now is
and will remain free and clear of any and all liens, charges, security
interests, encumbrances and adverse claims, except for the following ("Permitted
Liens"):  (i) purchase money security interests in specific items of equipment;
(ii) leases of specific items of equipment; (iii) liens for taxes not yet
payable; (iv) additional security interests and liens consented to in writing by
Silicon in its reasonable discretion, which consent shall not be unreasonably
withheld; and (v) security interests being terminated substantially concurrently
with this Agreement.  Silicon will have the right to require, as a condition to
its consent under subparagraph (iv) above, that the holder of the additional
security interest or lien sign an intercreditor agreement on Silicon's then
standard form, acknowledge that the security interest is subordinate to the
security interest in favor of Silicon, and agree not to take any action to
enforce its subordinate security interest so long as any Obligations remain
outstanding, and that the Borrower agree that any uncured default in any
obligation secured by the subordinate security interest shall also constitute an
Event of Default under this Agreement.  Silicon now has, and will continue to
have, a perfected and enforceable security interest in all of the Collateral,
subject only to the Permitted Liens, and the Borrower will at all times defend
Silicon and the Collateral against all claims of others.  None of the Collateral
now is or will be affixed to any real property in such a manner, or with such
intent, as to become a fixture.

 * AND SUBJECT TO THE PROVISIONS SET FORTH IN THE LAST SENTENCE OF SECTION 2.2
HEREOF

  3.5  MAINTENANCE OF COLLATERAL.  The Borrower will maintain the Collateral in
good working condition *, and the Borrower will not use the Collateral for any
unlawful purpose. The Borrower will immediately advise Silicon in writing of any
material loss or damage to the Collateral.

 * , SUBJECT TO ORDINARY WEAR AND TEAR

  3.6  BOOKS AND RECORDS.  The Borrower has maintained and will maintain at the
Borrower's Address complete and accurate books and records, comprising an
accounting system in accordance with generally accepted accounting principles.

  3.7  FINANCIAL CONDITION AND STATEMENTS.  All financial statements now or in
the future delivered to Silicon have been, and will be, prepared in conformity
with generally accepted accounting principles and now and in the future will
completely and accurately reflect the financial condition of the Borrower, at
the times and for the periods therein stated *.  Since the last date covered by
any such statement, there has been no material adverse change in the financial
condition or business of the Borrower.  The Borrower is now and will continue to
be solvent.  The Borrower will provide Silicon:  (i) within 30 days after the
end of each month, a monthly financial statement prepared by the Borrower, and a
Compliance Certificate in such form as Silicon shall reasonably specify, signed
by the Chief Financial Officer of the Borrower, certifying that as of the end of
such month the Borrower was in full compliance with all of the terms and
conditions of this Agreement, and setting forth calculations showing compliance
with the financial covenants set forth on the Schedule and such other
information as Silicon shall reasonably request; ** [and (ii) within 120 days
following the end of the Borrower's fiscal year, complete annual financial
statements, certified by independent certified public accountants acceptable to
Silicon.]

  * EXCEPT THAT ANY UNAUDITED QUARTERLY FINANCIAL STATEMENTS ARE SUBJECT TO YEAR
END ADJUSTMENTS

  ** (ii) WITHIN 5 DAYS AFTER THE EARLIER OF THE DATE THE REPORT 10-Q IS FILED
OR IS REQUIRED TO BE FILED WITH THE SECURITIES AND EXCHANGE COMMISSION, SUCH 10-
Q REPORT, A QUARTERLY FINANCIAL STATEMENT PREPARED BY THE BORROWER, AND A
COMPLIANCE CERTIFICATE, SIGNED BY THE CHIEF FINANCIAL OFFICER OF THE BORROWER,
CERTIFYING THAT THROUGHOUT SUCH QUARTER THE BORROWER WAS IN FULL COMPLIANCE WITH
ALL OF THE TERMS AND CONDITIONS OF THIS AGREEMENT, AND SETTING FORTH
CALCULATIONS SHOWING COMPLIANCE WITH THE FINANCIAL COVENANTS SET FORTH ON THE
SCHEDULE AND SUCH OTHER INFORMATION AS SILICON SHALL REASONABLY REQUEST; AND
(iii) WITHIN 5 DAYS AFTER THE EARLIER OF THE DATE THE REPORT 10-K IS FILED OR IS
REQUIRED TO BE FILED WITH THE SECURITIES AND EXCHANGE COMMISSION, SUCH 10-K
REPORT, COMPLETE ANNUAL FINANCIAL STATEMENTS, CERTIFIED BY INDEPENDENT CERTIFIED
PUBLIC ACCOUNTANTS FROM THE BIG SIX ACCOUNTING FIRMS OR SUCH OTHER INDEPENDENT
PUBLIC ACCOUNTANTS ACCEPTABLE TO SILICON, AND A COMPLIANCE CERTIFICATE FOR THE
QUARTER THEN ENDED, SIGNED BY THE CHIEF FINANCIAL OFFICER OF THE BORROWER,
CERTIFYING THAT THROUGHOUT SUCH QUARTER THE BORROWER WAS IN FULL COMPLIANCE WITH
ALL OF THE TERMS AND CONDITIONS OF THIS AGREEMENT, AND SETTING FORTH
CALCULATIONS SHOWING COMPLIANCE WITH THE FINANCIAL COVENANTS SET FORTH ON THE
SCHEDULE AND SUCH OTHER INFORMATION AS SILICON SHALL REASONABLY REQUEST.

  3.8  TAX RETURNS AND PAYMENTS; PENSION CONTRIBUTIONS.  The Borrower has timely
filed, and will timely file, all tax returns and reports required by foreign,
federal, state and local law, and the Borrower has timely paid, and will timely
pay, all foreign, federal, state and local taxes, assessments, deposits and
contributions now or in the future owed by the Borrower.  The Borrower may,
however, defer payment of any contested taxes, provided that the Borrower (i) in
good faith contests the Borrower's obligation to pay the taxes by appropriate
proceedings promptly and diligently instituted and conducted, (ii) notifies
Silicon in writing of the commencement of, and any material development in, the
proceedings, and (iii) posts bonds or takes any other steps required to keep the
contested taxes from becoming a lien upon any of the Collateral.  The Borrower
is unaware of any claims or adjustments proposed for any of the Borrower's prior
tax years which could result in additional taxes becoming due and payable by the
Borrower.  The Borrower has paid, and shall continue to pay all amounts
necessary to fund all 

                                      -3-
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Silicon Valley Bank                                  Loan and Security Agreement
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present and future pension, profit sharing and deferred compensation plans in
accordance with their terms, and the Borrower has not and will not withdraw from
participation in, permit partial or complete termination of, or permit the
occurrence of any other event with respect to, any such plan which could result
in any liability of the Borrower, including, without limitation, any liability
to the Pension Benefit Guaranty Corporation or its successors or any other
governmental agency.

  3.9  COMPLIANCE WITH LAW.  The Borrower has complied, and will comply, in all
material respects, with all provisions of all foreign, federal, state and local
laws and regulations relating to the Borrower, including, but not limited to,
those relating to the Borrower's ownership of real or personal property, conduct
and licensing of the Borrower's business, and environmental matters.

  3.10  LITIGATION.  Except as disclosed in the Schedule, there is no claim,
suit, litigation, proceeding or investigation pending or (to best of the
Borrower's knowledge) threatened by or against or affecting the Borrower in any
court or before any governmental agency (or any basis therefor known to the
Borrower) which may result, either separately or in the aggregate, in any
material adverse change in the financial condition or business of the Borrower,
or in any material impairment in the ability of the Borrower to carry on its
business in substantially the same manner as it is now being conducted.  The
Borrower will promptly inform Silicon in writing of any claim, proceeding,
litigation or investigation in the future threatened or instituted by or against
the Borrower involving amounts in excess of $100,000.

  3.11  USE OF PROCEEDS.  All proceeds of all Loans shall be used solely for
lawful business purposes.

4.  ADDITIONAL DUTIES OF THE BORROWER.

  4.1  FINANCIAL AND OTHER COVENANTS.  The Borrower shall at all times comply
with the financial and other covenants set forth in the Schedule to this
Agreement.

  4.2  OVERADVANCE; PROCEEDS OF ACCOUNTS.  If for any reason the total of all
outstanding Loans and all other Obligations exceeds the Credit Limit, without
limiting Silicon's other remedies, and whether or not Silicon declares an Event
of Default, Borrower shall remit to Silicon all checks and other proceeds of
Borrower's accounts and general intangibles, * in the same form as received by
Borrower, within one day after Borrower's receipt of the same, to be applied to
the Obligations in such order as Silicon shall determine in its discretion.

 * , TO THE EXTENT NOT PROHIBITED BY APPLICABLE LAW,

  4.3  INSURANCE.  The Borrower shall, at all times insure all of the tangible
personal property Collateral and carry such other business insurance, with
insurers reasonably acceptable to Silicon, in such form and amounts as Silicon
may reasonably require.  All such insurance policies shall name Silicon as an
additional loss payee, and shall contain a lenders loss payee endorsement in
form reasonably acceptable to Silicon.  Upon receipt of the proceeds of any such
insurance, Silicon shall apply such proceeds in reduction of the Obligations as
Silicon shall determine in its sole and absolute discretion, except that,
provided no Event of Default has occurred, Silicon shall release to the Borrower
insurance proceeds with respect to equipment totaling less than $100,000, which
shall be utilized by the Borrower for the replacement of the equipment with
respect to which the insurance proceeds were paid.  Silicon may require
reasonable assurance that the insurance proceeds so released will be so used.
If the Borrower fails to provide or pay for any insurance, Silicon may, but is
not obligated to, obtain the same at the Borrower's expense.  The Borrower shall
promptly deliver to Silicon copies of all reports made to insurance companies.

  4.4  REPORTS.  The Borrower shall provide Silicon with such written reports
with respect to the Borrower (including without limitation budgets, sales
projections, operating plans and other financial documentation), as Silicon
shall from time to time reasonably specify.

  4.5  ACCESS TO COLLATERAL, BOOKS AND RECORDS.  At all reasonable times, and
upon one business day notice, Silicon, or its agents, shall have the right to
inspect the Collateral, and the right to audit and copy the Borrower's
accounting books and records and Borrower's books and records relating to the
Collateral.  Silicon shall take reasonable steps to keep confidential all
information obtained in any such inspection or audit, but Silicon shall have the
right to disclose any such information to its auditors, regulatory agencies, and
* attorneys, and pursuant to any subpoena or other legal process.  The foregoing
audits shall be at Silicon's expense, except that the Borrower shall reimburse
Silicon for its reasonable [out of pocket] costs for semi-annual accounts
receivable audits by Silicon, its agents, or third parties retained by Silicon,
and Silicon may debit Borrower's deposit accounts with Silicon for the cost of
such semi-annual accounts receivable audits (in which event Silicon shall send
notification thereof to the Borrower). Notwithstanding the foregoing, after the
occurrence of an Event of Default all audits shall be at the Borrower's expense.

 * ITS

  4.6  NEGATIVE COVENANTS.  Except as may be permitted in the Schedule hereto,
the Borrower shall not, without Silicon's prior written consent, do any of the
following:  (i) merge or consolidate with another corporation, except that the
Borrower may merge or consolidate with another corporation if the Borrower is
the surviving corporation in the merger and the aggregate value of the assets
acquired in the merger do not exceed 25% of Borrower's Tangible Net Worth (as
defined in the Schedule) as of the end of the month prior to the effective date
of the merger, and the assets of the corporation acquired in the merger are not
subject to any liens or encumbrances, except Permitted Liens; (ii) acquire any
assets outside the ordinary course of business for an aggregate purchase price
exceeding 25% of Borrower's Tangible Net Worth (as defined in the Schedule) as
of the end of the month prior to the effective date of the acquisition; (iii)
enter into any other transaction outside the ordinary course of business (except
as permitted by the other provisions of this Section); (iv) sell 

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Silicon Valley Bank                                  Loan and Security Agreement
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or transfer any Collateral, except for the sale of finished inventory in the
ordinary course of the Borrower's business, and except for the sale of obsolete
or unneeded equipment in the ordinary course of business; (v) make any loans of
any money or any other assets; (vi) incur any debts, outside the ordinary course
of business, which would have a material, adverse effect on the Borrower or on
the prospect of repayment of the Obligations; (vii) guarantee or otherwise
become liable with respect to the obligations of another party or entity; (viii)
pay or declare any dividends on the Borrower's stock (except for dividends
payable solely in stock of the Borrower); (ix) redeem, retire, purchase or
otherwise acquire, directly or indirectly, any of the Borrower's stock; (x) make
any change in the Borrower's capital structure which has a material adverse
effect on the Borrower or on the prospect of repayment of the Obligations; or
(xi) dissolve or elect to dissolve. Transactions permitted by the foregoing
provisions of this Section are only permitted if no Event of Default and no
event which (with notice or passage of time or both) would constitute an Event
of Default would occur as a result of such transaction.

  4.7  LITIGATION COOPERATION.  Should any third-party suit or proceeding be
instituted by or against Silicon with respect to any Collateral or in any manner
relating to the Borrower, the Borrower shall, without expense to Silicon, make
available the Borrower and its officers, employees and agents and the Borrower's
books and records to the extent that Silicon may deem them reasonably necessary
in order to prosecute or defend any such suit or proceeding.

  4.8  VERIFICATION.  Silicon may, from time to time, following prior
notification to Borrower, verify directly with the respective account debtors
the validity, amount and other matters relating to the Borrower's accounts, by
means of mail, telephone or otherwise, either in the name of the Borrower or
Silicon or such other name as Silicon may reasonably choose, provided that no
prior notification to Borrower shall be required following an Event of Default.

  4.9  EXECUTE ADDITIONAL DOCUMENTATION.  The Borrower agrees, at its expense,
on request by Silicon, to execute all documents in form satisfactory to Silicon,
as Silicon, may deem reasonably necessary or useful in order to perfect and
maintain Silicon's perfected security interest in the Collateral, and in order
to fully consummate all of the transactions contemplated by this Agreement.

5.  TERM.

  5.1  MATURITY DATE.  This Agreement shall continue in effect until the
maturity date set forth on the Schedule hereto (the "Maturity Date").

  5.2  EARLY TERMINATION.  This Agreement may be terminated, without penalty,
prior to the Maturity Date as follows:  (i) by the Borrower, effective three
business days after written notice of termination is given to Silicon; or (ii)
by Silicon at any time after the occurrence of an Event of Default, without
notice, effective immediately.

  5.3  PAYMENT OF OBLIGATIONS.  On the Maturity Date or on any earlier effective
date of termination, the Borrower shall pay and perform in full all Obligations,
whether evidenced by installment notes or otherwise, and whether or not all or
any part of such Obligations are otherwise then due and payable. Without
limiting the generality of the foregoing, if on the Maturity Date, or on any
earlier effective date of termination, there are any outstanding letters of
credit issued by Silicon or issued by another institution based upon an
application, guarantee, indemnity or similar agreement on the part of Silicon,
then on such date Borrower shall provide to Silicon cash collateral in an amount
equal to the face amount of all such letters of credit plus all interest, fees
and cost due or to become due in connection therewith, to secure all of the
Obligations relating to said letters of credit, pursuant to Silicon's then
standard form cash pledge agreement. Notwithstanding any termination of this
Agreement, all of Silicon's security interests in all of the Collateral and all
of the terms and provisions of this Agreement shall continue in full force and
effect until all Obligations have been paid and performed in full; provided
that, without limiting the fact that Loans are subject to the reasonable
discretion of Silicon, Silicon may, in its sole discretion, refuse to make any
further Loans after termination. No termination shall in any way affect or
impair any right or remedy of Silicon, nor shall any such termination relieve
the Borrower of any Obligation to Silicon, until all of the Obligations have
been paid and performed in full. Upon payment and performance in full of all the
Obligations, Silicon shall promptly deliver to the Borrower termination
statements, requests for reconveyances and such other documents as may be
required to fully terminate any of Silicon's security interests.

6.  EVENTS OF DEFAULT AND REMEDIES.

  6.1  EVENTS OF DEFAULT.  The occurrence of any of the following events shall
constitute an "Event of Default" under this Agreement, and the Borrower shall
give Silicon immediate written notice thereof:  (a) Any warranty,
representation, statement, report or certificate made or delivered to Silicon by
the Borrower or any of the Borrower's officers, employees or agents, now or in
the future, shall be untrue or misleading in any material respect; or (b) the
Borrower shall fail to pay when due any Loan or any interest thereon or any
other monetary Obligation; or (c) the total Loans and other Obligations
outstanding at any time exceed the Credit Limit; or (d) the Borrower shall fail
to comply with any of the financial covenants set forth in the Schedule or shall
fail to perform any other non-monetary Obligation which by its nature cannot be
cured; or (e) the Borrower shall fail to pay or perform any other non-monetary
Obligation, which failure is not cured within [5] * business days after the date
due; or (f) Any levy, assessment, attachment, seizure, lien or encumbrance is
made on all or any part of the Collateral which is not cured within [10] ** days
after the occurrence of the same; or (g) Dissolution, termination of existence,
insolvency or business failure of the Borrower; or appointment of a receiver,
trustee or custodian, for all or any part of the property of, assignment for the
benefit of

                                      -5-
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Silicon Valley Bank                                  Loan and Security Agreement
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creditors by, or the commencement of any proceeding by the Borrower under any
reorganization, bankruptcy, insolvency, arrangement, readjustment of debt,
dissolution or liquidation law or statute of any jurisdiction, now or in the
future in effect; or (h) the commencement of any proceeding against the Borrower
or any guarantor of any of the Obligations under any reorganization, bankruptcy,
insolvency, arrangement, readjustment of debt, dissolution or liquidation law or
statute of any jurisdiction, now or in the future in effect, which is not cured
by the dismissal thereof within 30 days after the date commenced; (i) revocation
or termination of, or limitation or denial of liability upon, any guaranty of
the Obligations or any attempt to do any of the foregoing; or commencement of
proceedings by any guarantor of any of the Obligations under any bankruptcy or
insolvency law; or (j) revocation or termination of, or limitation or denial of
liability upon, any pledge of any certificate of deposit, securities or other
property or asset of any kind pledged by any third party to secure any or all of
the Obligations, or any attempt to do any of the foregoing; or commencement of
proceedings by or against any such third party under any bankruptcy or
insolvency law, ***; or (k) the Borrower makes any payment on account of any
indebtedness or obligation which has been subordinated to the Obligations other
than as permitted in the applicable subordination agreement or if any person who
has subordinated such indebtedness or obligations terminates or in any way
limits his subordination agreement; or (l) there shall be a change in [the
record or beneficial ownership of an aggregate of more than 20% of the
outstanding shares of stock] **** of the Borrower, in one or more transactions,
compared to the ownership of outstanding shares of stock of the Borrower in
effect on the date hereof, without the prior written consent of Silicon; or (m)
a material adverse change occurs in the business, operations, or financial or
other condition of the Borrower, or a material impairment occurs in the prospect
of payment of the Obligations, or there is a material impairment of the value or
priority of Silicon's security interest in the Collateral; or (n) the Borrower
shall generally not pay its debts as they become due; or the Borrower shall
conceal, remove or transfer any part of its property, with intent to hinder,
delay or defraud its creditors, or make or suffer any transfer of any of its
property which may be fraudulent under any bankruptcy, fraudulent conveyance or
similar law. Silicon may cease making any Loans hereunder during any of the
above cure periods, and thereafter if an Event of Default has occurred.

 * 10

 ** 20

  *** PROVIDED THAT WITH RESPECT TO THE COMMENCEMENT OF PROCEEDINGS AGAINST ANY
      --------                                                                 
SUCH THIRD PARTY UNDER ANY BANKRUPTCY OR INSOLVENCY LAW, AN EVENT OF DEFAULT
SHALL ONLY ARISE WHEN SUCH PROCEEDINGS ARE NOT CURED BY THE DISMISSAL THEREOF
WITHIN 30 DAYS AFTER THE DATE COMMENCED

 **** CONTROL

  6.2  REMEDIES.  Upon the occurrence of any Event of Default, and at any time
thereafter, Silicon, at its option, and without notice or demand of any kind
(all of which are hereby expressly waived by the Borrower), may do any one or
more of the following:  (a) Cease making Loans and cease extending letters of
credit or other credit facilities to or for the benefit of the Borrower under
this Agreement or any other document or agreement; (b) Accelerate and declare
all or any part of the Obligations to be immediately due, payable, and
performable, notwithstanding any deferred or installment payments allowed by any
instrument evidencing or relating to any Obligation; (c) Take possession of any
or all of the Collateral wherever it may be found, and for that purpose the
Borrower hereby authorizes Silicon without judicial process to enter onto any of
the Borrower's premises without interference to search for, take possession of,
keep, store, or remove any of the Collateral, and remain on the premises or
cause a custodian to remain on the premises in exclusive control thereof without
charge for so long as Silicon deems it reasonably necessary in order to complete
the enforcement of its rights under this Agreement or any other agreement;
provided, however, that should Silicon seek to take possession of any or all of
the Collateral by Court process, the Borrower hereby irrevocably waives:  (i)
any bond and any surety or security relating thereto required by any statute,
court rule or otherwise as an incident to such possession; (ii) any demand for
possession prior to the commencement of any suit or action to recover possession
thereof; and (iii) any requirement that Silicon retain possession of and not
dispose of any such Collateral until after trial or final judgment; (d) Require
the Borrower to assemble any or all of the Collateral and make it available to
Silicon at places designated by Silicon which are reasonably convenient to
Silicon and the Borrower, and to remove the Collateral to such locations as
Silicon may deem advisable; (e) Require Borrower to deliver to Silicon, in kind,
all checks and other payments received with respect to all accounts and general
intangibles, together with any necessary indorsements, within one day after the
date received by the Borrower; (f) Complete the processing, manufacturing or
repair of any Collateral prior to a disposition thereof and, for such purpose
and for the purpose of removal, Silicon shall have the right to use the
Borrower's premises, vehicles, hoists, lifts, cranes, equipment and all other
property without charge; (g) Sell, lease or otherwise dispose of any of the
Collateral in its condition at the time Silicon obtains possession of it or
after further manufacturing, processing or repair, at any one or more public
and/or private sales, in lots or in bulk, for cash, exchange or other property,
or on credit, and to adjourn any such sale from time to time without notice
other than oral announcement at the time scheduled for sale. Silicon shall have
the right to conduct such disposition on the Borrower's premises without charge,
for such time or times as Silicon deems reasonable, or on Silicon's premises, or
elsewhere and the Collateral need not be located at the place of disposition.
Silicon may directly or through any affiliated company purchase or lease any
Collateral at any such public disposition, and if permissible under applicable
law, at any private 

                                      -6-
<PAGE>
 
Silicon Valley Bank                                  Loan and Security Agreement
--------------------------------------------------------------------------------

disposition. Any sale or other disposition of Collateral shall not relieve the
Borrower of any liability the Borrower may have if any Collateral is defective
as to title or physical condition or otherwise at the time of sale; (h) Demand
payment of, and collect any accounts and general intangibles comprising
Collateral and, in connection therewith, the Borrower irrevocably authorizes
Silicon to endorse or sign the Borrower's name on all collections, receipts,
instruments and other documents, to take possession of and open mail addressed
to the Borrower and remove therefrom payments made with respect to any item of
the Collateral or proceeds thereof, and, in Silicon's sole discretion, to grant
extensions of time to pay, compromise claims and settle accounts and the like
for less than face value; (i) Offset against any sums in any of Borrower's
general, special or other deposit accounts with Silicon; and (j) Demand and
receive possession of any of the Borrower's federal and state income tax returns
and the books and records utilized in the preparation thereof or referring
thereto. All reasonable attorneys' fees, expenses, costs, liabilities and
obligations incurred by Silicon with respect to the foregoing shall be added to
and become part of the Obligations, shall be due on demand, and shall bear
interest at a rate equal to the highest interest rate applicable to any of the
Obligations. Without limiting any of Silicon's rights and remedies, from and
after the occurrence of any Event of Default, the interest rate applicable to
the Obligations shall be increased by an additional five percent per annum.

  6.3  STANDARDS FOR DETERMINING COMMERCIAL REASONABLENESS.  The Borrower and
Silicon agree that a sale or other disposition (collectively, "sale") of any
Collateral which complies with the following standards will conclusively be
deemed to be commercially reasonable:  (i) Notice of the sale is given to the
Borrower at least seven days prior to the sale, and, in the case of a public
sale, notice of the sale is published at least seven days before the sale in a
newspaper of general circulation in the county where the sale is to be
conducted; (ii) Notice of the sale describes the collateral in general, non-
specific terms; (iii) The sale is conducted at a place designated by Silicon,
with or without the Collateral being present; (iv) The sale commences at any
time between 8:00 a.m. and 6:00 p.m; (v) Payment of the purchase price in cash
or by cashier's check or wire transfer is required; (vi) With respect to any
sale of any of the Collateral, Silicon may (but is not obligated to) direct any
prospective purchaser to ascertain directly from the Borrower any and all
information concerning the same.  Silicon may employ other methods of noticing
and selling the Collateral, in its discretion, if they are commercially
reasonable.

  6.4  POWER OF ATTORNEY.  Upon the occurrence of any Event of Default, without
limiting Silicon's other rights and remedies, the Borrower grants to Silicon an
irrevocable power of attorney coupled with an interest, authorizing and
permitting Silicon (acting through any of its employees, attorneys or agents) at
any time, at its option, but without obligation, with or without notice to the
Borrower, and at the Borrower's expense, to do any or all of the following, in
the Borrower's name or otherwise: (a) Execute on behalf of the Borrower any
documents that Silicon may, in its sole and absolute discretion, deem advisable
in order to perfect and maintain Silicon's security interest in the Collateral,
or in order to exercise a right of the Borrower or Silicon, or in order to fully
consummate all the transactions contemplated under this Agreement, and all other
present and future agreements; (b) Execute on behalf of the Borrower any
document exercising, transferring or assigning any option to purchase, sell or
otherwise dispose of or to lease (as lessor or lessee) any real or personal
property which is part of Silicon's Collateral or in which Silicon has an
interest; (c) Execute on behalf of the Borrower, any invoices relating to any
account, any draft against any account debtor and any notice to any account
debtor, any proof of claim in bankruptcy, any Notice of Lien, claim of
mechanic's, materialman's or other lien, or assignment or satisfaction of
mechanic's, materialman's or other lien; (d) Take control in any manner of any
cash or non-cash items of payment or proceeds of Collateral; endorse the name of
the Borrower upon any instruments, or documents, evidence of payment or
Collateral that may come into Silicon's possession; (e) Endorse all checks and
other forms of remittances received by Silicon; (f) Pay, contest or settle any
lien, charge, encumbrance, security interest and adverse claim in or to any of
the Collateral, or any judgment based thereon, or otherwise take any action to
terminate or discharge the same; (g) Grant extensions of time to pay, compromise
claims and settle accounts and general intangibles for less than face value and
execute all releases and other documents in connection therewith; (h) Pay any
sums required on account of the Borrower's taxes or to secure the release of any
liens therefor, or both; (i) Settle and adjust, and give releases of, any
insurance claim that relates to any of the Collateral and obtain payment
therefor; (j) Instruct any third party having custody or control of any books or
records belonging to, or relating to, the Borrower to give Silicon the same
rights of access and other rights with respect thereto as Silicon has under this
Agreement; and (k) Take any action or pay any sum required of the Borrower
pursuant to this Agreement and any other present or future agreements. Silicon
shall exercise the foregoing powers in a commercially reasonable manner. Any and
all reasonable sums paid and any and all reasonable costs, expenses,
liabilities, obligations and attorneys' fees incurred by Silicon with respect to
the foregoing shall be added to and become part of the Obligations, shall be
payable on demand, and shall bear interest at a rate equal to the highest
interest rate applicable to any of the Obligations. In no event shall Silicon's
rights under the foregoing power of attorney or any of Silicon's other rights
under this Agreement be deemed to indicate that Silicon is in control of the
business, management or properties of the Borrower.

  6.5  APPLICATION OF PROCEEDS.  All proceeds realized as the result of any sale
of the Collateral shall be applied by Silicon first to the costs, expenses,
liabilities, obligations and attorneys' fees incurred by Silicon in the exercise
of its rights under this Agreement, second to the interest due upon any of the
Obligations, and third to the principal of 

                                      -7-
<PAGE>
 
Silicon Valley Bank                                  Loan and Security Agreement
--------------------------------------------------------------------------------

the Obligations, in such order as Silicon shall determine in its sole
discretion. Any surplus shall be paid to the Borrower or other persons legally
entitled thereto; the Borrower shall remain liable to Silicon for any
deficiency. If, Silicon, in its sole discretion, directly or indirectly enters
into a deferred payment or other credit transaction with any purchaser at any
sale or other disposition of Collateral, Silicon shall have the option,
exercisable at any time, in its sole discretion, of either reducing the
Obligations by the principal amount of purchase price or deferring the reduction
of the Obligations until the actual receipt by Silicon of the cash therefor.

  6.6  REMEDIES CUMULATIVE.  In addition to the rights and remedies set forth in
this Agreement, Silicon shall have all the other rights and remedies accorded a
secured party under the California Uniform Commercial Code and under all other
applicable laws, and under any other instrument or agreement now or in the
future entered into between Silicon and the Borrower, and all of such rights and
remedies are cumulative and none is exclusive.  Exercise or partial exercise by
Silicon of one or more of its rights or remedies shall not be deemed an
election, nor bar Silicon from subsequent exercise or partial exercise of any
other rights or remedies.  The failure or delay of Silicon to exercise any
rights or remedies shall not operate as a waiver thereof, but all rights and
remedies shall continue in full force and effect until all of the Obligations
have been fully paid and performed.

7.  GENERAL PROVISIONS.

  7.1  CREDITING PAYMENTS.  Payments shall not be applied to the Obligations
until received by Silicon in immediately available federal funds, and any wire
transfer or other payment so received after 12:00 noon Pacific time shall be
deemed to have been received by Silicon as of the opening of business on the
next business day.

  7.2  NOTICES.  All notices to be given under this Agreement shall be in
writing and shall be given either personally or by regular first-class mail, or
certified mail return receipt requested, addressed to Silicon or the Borrower at
the addresses shown in the heading to this Agreement, or at any other address
designated in writing by one party to the other party.  All notices shall be
deemed to have been given upon delivery in the case of notices personally
delivered to the Borrower or to Silicon, or at the expiration of two business
days following the deposit thereof in the United States mail, with postage
prepaid.

  7.3  SEVERABILITY.  Should any provision of this Agreement be held by any
court of competent jurisdiction to be void or unenforceable, such defect shall
not affect the remainder of this Agreement, which shall continue in full force
and effect.

  7.4  INTEGRATION.  This Agreement and such other written agreements, documents
and instruments as may be executed in connection herewith are the final, entire
and complete agreement between the Borrower and Silicon and supersede all prior
and contemporaneous negotiations and oral representations and agreements, all of
which are merged and integrated in this Agreement.  There are no oral
                                                    -----------------
understandings, representations or agreements between the parties which are not
-------------------------------------------------------------------------------
set forth in this Agreement or in other written agreements signed by the parties
--------------------------------------------------------------------------------
in connection herewith.
-----------------------

  7.5  WAIVERS.  The failure of Silicon at any time or times to require the
Borrower to strictly comply with any of the provisions of this Agreement or any
other present or future agreement between the Borrower and Silicon shall not
waive or diminish any right of Silicon later to demand and receive strict
compliance therewith.  Any waiver of any default shall not waive or affect any
other default, whether prior or subsequent thereto.  None of the provisions of
this Agreement or any other agreement now or in the future executed by the
Borrower and delivered to Silicon shall be deemed to have been waived by any act
or knowledge of Silicon or its agents or employees, but only by a specific
written waiver signed by an officer of Silicon and delivered to the Borrower.
The Borrower waives demand, protest, notice of protest and notice of default or
dishonor, notice of payment and nonpayment, release, compromise, settlement,
extension or renewal of any commercial paper, instrument, account, general
intangible, document or guaranty at any time held by Silicon on which the
Borrower is or may in any way be liable, and notice of any action taken by
Silicon, unless expressly required by this Agreement.

  7.6  NO LIABILITY FOR ORDINARY NEGLIGENCE.  Neither Silicon, nor any of its
directors, officers, employees, agents, attorneys or any other person affiliated
with or representing Silicon shall be liable for any claims, demands, losses or
damages, of any kind whatsoever, made, claimed, incurred or suffered by the
Borrower or any other party through the ordinary negligence of Silicon, or any
of its directors, officers, employees, agents, attorneys or any other person
affiliated with or representing Silicon.

  7.7  AMENDMENT.  The terms and provisions of this Agreement may not be waived
or amended, except in a writing executed by the Borrower and a duly authorized
officer of Silicon.

  7.8  TIME OF ESSENCE.  Time is of the essence in the performance by the
Borrower of each and every obligation under this Agreement.

  7.9  ATTORNEYS FEES AND COSTS.  The Borrower shall reimburse Silicon for all
reasonable attorneys' fees and all filing, recording, search, title insurance,
appraisal, audit, and other reasonable costs incurred by Silicon, pursuant to,
or in connection with, or relating to this Agreement (whether or not a lawsuit
is filed), including, but not limited to, any reasonable attorneys' fees and
costs Silicon incurs in order to do the following:  prepare and negotiate this
Agreement and the documents relating to this Agreement; obtain legal advice in
connection with this Agreement; enforce, or seek to enforce, any of its rights;
prosecute actions against, or defend actions by, account debtors; commence,
intervene in, or defend any action or proceeding; initiate any complaint to be
relieved of the 

                                      -8-
<PAGE>
 
Silicon Valley Bank                                  Loan and Security Agreement
--------------------------------------------------------------------------------

automatic stay in bankruptcy; file or prosecute any probate claim, bankruptcy
claim, third-party claim, or other claim; examine, audit, copy, and inspect any
of the Collateral or any of the Borrower's books and records; protect, obtain
possession of, lease, dispose of, or otherwise enforce Silicon's security
interest in, the Collateral; and otherwise represent Silicon in any litigation
relating to the Borrower. In satisfying Borrower's obligation hereunder to
                          ------------------------------------------------
reimburse Silicon for attorneys fees, Borrower may, for convenience, issue
--------------------------------------------------------------------------
checks directly to Silicon's attorneys, Levy, Small & Lallas, but Borrower
--------------------------------------------------------------------------
acknowledges and agrees that Levy, Small & Lallas is representing only Silicon
------------------------------------------------------------------------------
and not Borrower in connection with this Agreement. If either Silicon or the
---------------------------------------------------
Borrower files any lawsuit against the other predicated on a breach of this
Agreement, the prevailing party in such action shall be entitled to recover its
reasonable costs and attorneys' fees, including (but not limited to) reasonable
attorneys' fees and costs incurred in the enforcement of, execution upon or
defense of any order, decree, award or judgment. All attorneys' fees and costs
to which Silicon may be entitled pursuant to this Paragraph shall immediately
become part of the Borrower's Obligations, shall be due on demand, and shall
bear interest at a rate equal to the highest interest rate applicable to any of
the Obligations.

  7.10  BENEFIT OF AGREEMENT.  The provisions of this Agreement shall be binding
upon and inure to the benefit of the respective successors, assigns, heirs,
beneficiaries and representatives of the parties hereto; provided, however, that
the Borrower may not assign or transfer any of its rights under this Agreement
without the prior written consent of Silicon, and any prohibited assignment
shall be void.  No consent by Silicon to any assignment shall release the
Borrower from its liability for the Obligations.

  7.11  JOINT AND SEVERAL LIABILITY.  If the Borrower consists of more than one
person, their liability shall be joint and several, and the compromise of any
claim with, or the release of, any Borrower shall not constitute a compromise
with, or a release of, any other Borrower.

  7.12  PARAGRAPH HEADINGS; CONSTRUCTION.  Paragraph headings are only used in
this Agreement for convenience.  The Borrower acknowledges that the headings may
not describe completely the subject matter of the applicable paragraph, and the
headings shall not be used in any manner to construe, limit, define or interpret
any term or provision of this Agreement.  This Agreement has been fully reviewed
and negotiated between the parties and no uncertainty or ambiguity in any term
or provision of this Agreement shall be construed strictly against Silicon or
the Borrower under any rule of construction or otherwise.

  7.13  GOVERNING LAW; JURISDICTION; VENUE.  This Agreement and all acts and
transactions hereunder and all rights and obligations of Silicon and the
Borrower shall be governed by, and in accordance with, the laws of the State of
California.  Any undefined term used in this Agreement that is defined in the
California Uniform Commercial Code shall have the meaning assigned to that term
in the California Uniform Commercial Code.  As a material part of the
consideration to Silicon to enter into this Agreement, the Borrower (i) agrees
that all actions and proceedings relating directly or indirectly hereto shall,
at Silicon's option, be litigated in courts located within California, and that
the exclusive venue therefor shall be Orange County; (ii) consents to the
jurisdiction and venue of any such court and consents to service of process in
any such action or proceeding by personal delivery or any other method permitted
by law; and (iii) waives any and all rights the Borrower may have to object to
the jurisdiction of any such court, or to transfer or change the venue of any
such action or proceeding.

  7.14  MUTUAL WAIVER OF JURY TRIAL.  THE BORROWER AND SILICON EACH HEREBY WAIVE
THE RIGHT TO TRIAL BY JURY IN ANY ACTION OR PROCEEDING BASED UPON, ARISING OUT
OF, OR IN ANY WAY RELATING TO, THIS AGREEMENT OR ANY OTHER PRESENT OR FUTURE
INSTRUMENT OR AGREEMENT BETWEEN SILICON AND THE BORROWER, OR ANY CONDUCT, ACTS
OR OMISSIONS OF SILICON OR THE BORROWER OR ANY OF THEIR DIRECTORS, OFFICERS,
EMPLOYEES, AGENTS, ATTORNEYS OR ANY OTHER PERSONS AFFILIATED WITH SILICON OR THE
BORROWER.  THIS WAIVER OF THE RIGHT TO JURY TRIAL APPLIES TO ALL CONTRACT
CLAIMS, TORT CLAIMS, BREACH OF DUTY CLAIMS, COMMON LAW CLAIMS, STATUTORY CLAIMS
AND ALL OTHER CLAIMS AND CAUSES OF ACTION OF EVERY KIND.  EACH PARTY RECOGNIZES
AND AGREES THAT THE FOREGOING JURY TRIAL WAIVER CONSTITUTES A MATERIAL
INDUCEMENT TO THE OTHER PARTY TO ENTER INTO THIS AGREEMENT.  EACH PARTY
REPRESENTS AND WARRANTS THAT IT HAS REVIEWED THIS JURY TRIAL WAIVER WITH ITS
LEGAL COUNSEL AND THAT IT KNOWINGLY AND VOLUNTARILY WAIVES ITS JURY TRIAL RIGHTS
FOLLOWING ITS CONSULTATION WITH ITS LEGAL COUNSEL.

Borrower:

  NETVANTAGE, INC.


  By /s/ Stephen R. Rizzone
    ----------------------------
    President or Vice President


  By /s/ Thomas V. Baker
    ----------------------------
    Secretary or Ass't Secretary


Silicon:

  SILICON VALLEY BANK


  By /s/ [SIGNATURE APPEARS HERE]
    ----------------------------
  Title  Sr. Vice President
         ------------------
                                      -9-
<PAGE>
 
 
[LOGO OF SILICON VALLEY BANK]

                          AMENDMENT TO LOAN AGREEMENT

BORROWER:  NETVANTAGE, INC.
ADDRESS:   201 CONTINENTAL BOULEVARD, SUITE 201
           EL SEGUNDO, CALIFORNIA  90245

DATE:      AUGUST 16, 1996

    THIS AMENDMENT TO LOAN AGREEMENT is entered into between SILICON VALLEY BANK
("Silicon") and the borrower named above (the "Borrower").  The Parties agree to
amend the Loan and Security Agreement between them dated July 15, 1996, as
amended from time to time (the "Loan Agreement"), as follows, effective as of
the date hereof.  (Capitalized terms used but not defined in this Amendment,
shall have the meanings set forth in the Loan Agreement.)

    1.  AMENDED SCHEDULE.  The Schedule to Loan Agreement is hereby amended to
read as set forth in the Schedule to Loan Agreement attached hereto.

    2.  FEE.  The Borrower shall pay Silicon concurrently herewith a fee of
$22,500.  Said fee shall be in addition to all interest and other sums payable
to Silicon, and shall not be refundable.

    3.  REPRESENTATIONS TRUE.  Borrower represents and warrants to Silicon that
all representations and warranties set forth in the Loan Agreement, as amended
hereby, are true and correct.

    4.  GENERAL PROVISIONS.  This Amendment, the Loan Agreement, any prior
written amendments to the Loan Agreement signed by Silicon and the Borrower, and
the other written documents and agreements between Silicon and the Borrower set
forth in full all of the representations and agreements of the parties with
respect to the subject matter hereof and supersede all prior discussions,
representations, agreements and understandings between the parties with respect
to the subject hereof.  Except as herein expressly amended, all of the terms and
provisions of the Loan Agreement, and all other documents and agreements between
Silicon and the Borrower shall continue in full force and effect and the same
are hereby ratified and confirmed.

BORROWER:                                 SILICON:

NETVANTAGE, INC.                          SILICON VALLEY BANK

By /s/ Stephen R. Rizzone                 By /s/ [SIGNATURE APPEARS HERE]
  ----------------------------              -----------------------------
  President or Vice President               Title  Vice President
                                                  -----------------------

By /s/ Thomas V. Baker
  ----------------------------
  Secretary or Ass't Secretary

                                      -1-
<PAGE>
 
[LOGO OF SILICON VALLEY BANK]

                                  SCHEDULE TO
                          LOAN AND SECURITY AGREEMENT

BORROWER:  NETVANTAGE, INC.

ADDRESS:   201 CONTINENTAL BOULEVARD, SUITE 201
           EL SEGUNDO, CALIFORNIA  90245

DATE:      AUGUST 16, 1996

     THIS SCHEDULE is an integral part of the Loan and Security Agreement
between Silicon Valley Bank ("Silicon") and the above-named borrower
("Borrower") of even date.

CREDIT LIMIT
(Section 1.1):      An amount not to exceed the lesser of:  (i) $5,000,000 at
                    any one time outstanding; or (ii) 70% of the Net Amount of
                    Borrower's accounts, which Silicon in its discretion deems
                    eligible for borrowing.  "Net Amount" of an account means
                    the gross amount of the account, minus all applicable sales,
                    use, excise and other similar taxes and minus all discounts,
                    credits and allowances of any nature granted or claimed.
                    Loans that are made based on Borrower's eligible accounts as
                    described herein are referred to as the "Accounts Loans."

                    Without limiting the fact that the determination of which
                    accounts are eligible for borrowing is a matter of Silicon's
                    discretion, the following will not be deemed eligible for
                    borrowing:  (a) accounts outstanding for more than 90 days
                    from the invoice date*; (b) accounts subject to any
                    contingencies, or arising from a consignment, guaranteed
                    sale, bill and hold, sale on approval or other transaction
                    in which payment by the account debtor is conditional; (c)
                    accounts owing from the United States or any department,
                    agency or instrumentality of the United States or any state,
                    city or municipality; (d) accounts owing from an account
                    debtor whose chief executive office or principal place of
                    business is outside the United States (unless the account is
                    pre-approved by Silicon in its discretion, or backed by a
                    letter of credit satisfactory to Silicon, or FCIA insured
                    satisfactory to Silicon, or the account arises from goods
                    shipped or services rendered to a branch or office of the
                    account debtor in the United States)**; (e) accounts owing
                    from one account debtor to the extent they exceed 25% of the
                    total eligible accounts outstanding***; (f) accounts owing
                    from an affiliate of Borrower****; and (g) accounts owing
                    from an account debtor to whom Borrower is or may be liable
                    for goods purchased from, or services received from, such
                    account debtor or otherwise (to the extent of the amount
                    owing to such account debtor).  In addition, if more than
                    50% of the accounts owing from an account debtor are
                    outstanding more than 90 days***** from the invoice date or
                    are otherwise not eligible for borrowing, then all accounts
                    owing from that account debtor will be deemed ineligible for
                    borrowing.
<PAGE>
 
Silicon Valley Bank                      Schedule to Loan and Security Agreement
--------------------------------------------------------------------------------

                    * OTHER THAN FOR THE APPROVED FOREIGN DEBTORS FOR WHICH SUCH
                    NUMBER OF DAYS SHALL BE NO MORE THAN 120 DAYS FROM THE
                    INVOICE DATE

                    ** OTHER THAN WITH RESPECT TO SIEMENS, ALLIED TELESIS KK,
                    NEXTCOM KK AND OLIVETTI (THE "APPROVED FOREIGN DEBTORS")

                    *** OTHER THAN WITH RESPECT TO IBM, HEWLETT PACKARD, UB
                    NETWORKS AND/OR BAY NETWORKS, FOR WHICH THIS PERCENTAGE
                    AMOUNT SHALL BE 50%.

                    **** (OTHER THAN WITH RESPECT TO UB NETWORKS AND NEXTCOM KK)

                    ***** OR 120 DAYS IN THE CASE OF THE APPROVED FOREIGN
                    DEBTORS

PLUS
----
TERM LOANS          Borrower shall also have the option to convert up to
                    $1,000,000, in the aggregate, of Accounts Loans to term
                    loans (individually a "Term Loan" and collectively referred
                    to as the "Term Loans") during the period starting on the
                    original date of the Loan Agreement and ending on the date
                    twelve months thereafter, subject, however, to the
                                              -------  -------        
                    Borrower's satisfaction of all of the Conversion
                    Requirements (as defined below) in a manner satisfactory to
                    Silicon in its discretion (the date of the making of each
                    Term Loan is referred to as the "Term Loan Date").
                    Conversion of an Accounts Loan to a Term Loan as set forth
                    herein reinstates availability under the Credit Limit
                    regarding Accounts Loans up to the initial principal amount
                    of such Term Loan, provided that Accounts Loans in such an
                                       --------                               
                    amount are otherwise available to the Borrower pursuant to
                    the terms hereof.  The minimum amount of a Term Loan shall
                    be $250,000.  This option to convert Accounts Loans to Term
                    Loans is not a revolving facility and therefore repayment of
                    principal amounts of the Term Loans does not create
                    additional availability for the making of new Term Loans.

                    The principal balance of each Term Loan shall be repaid by
                    the Borrower to Silicon in 36 equal monthly principal
                    payments, commencing one month after the Term Loan Date and
                    continuing thereafter for 35 months, on which final payment
                    date the entire unpaid balance of such Term Loan and all
                    other Obligations relating thereto shall be due and payable.
                    In addition to making such indicated principal payments,
                    Borrower shall pay to Silicon interest on the principal
                    amount of the Term Loans outstanding from time to time in
                    accordance with Section 1.2 of the Loan Agreement.

                    The term "Conversion Requirements" means all of the
                    following:

                    (a)  Borrower's providing written notice to Silicon stating
                    its desire to convert a stated amount of its Accounts Loans
                    to a Term Loan, subject to the terms and provisions of this
                    Agreement;

                    (b)  Borrower's providing written and other evidence
                    satisfactory to Silicon in its discretion that the requested
                    amount of the Term Loan is equal to or less than the sum of
                    (i) 80% of the sum of the invoice amounts of new items of
                    equipment that the Borrower purchases after the date of this
                    Agreement, satisfactory to Silicon in its discretion; (ii)
                    25% of the sum of the invoice amounts of software items that
                    the Borrower purchases after the date of this Agreement,
                    satisfactory to Silicon in its discretion; plus (iii) 25% of
                                                               ----             
                    the aggregate amount of expenditures Borrower makes after
                    the date of this Agreement on improvements to its leasehold
                    premises not otherwise included in items (i) and (ii) hereof
                    (the "Leasehold Improvements"), relating to a lease
                    remaining in effect for a time 

                                      -2-
<PAGE>
 
Silicon Valley Bank                      Schedule to Loan and Security Agreement
--------------------------------------------------------------------------------

                    period at least equal to the repayment term of proposed Term
                    Loan and for such improvements that Silicon determines are
                    acceptable in its discretion;

                    (c)  if the Borrower includes Leasehold Improvements in the
                    above calculation, Borrower's execution and delivery to
                    Silicon of UCC fixture filings relating to the Leasehold
                    Improvements such that Silicon establishes a first priority
                    perfected security interest therein and the execution and
                    delivery to Silicon of landlord waivers, in each case in
                    form and substance satisfactory to Silicon in its
                    discretion;

                    (d)  Borrower's providing written and other evidence
                    satisfactory to Silicon that it has complied with either the
                    Debt Service Ratio (relating to the Borrower's most recent
                    two fiscal quarters) or the Liquidity Coverage Ratio
                    (relating to the Borrower's most recent month end period),
                    as such ratios are set forth in Section 4.1 of this
                    Schedule;

                    (e)  Borrower's payment to Silicon of a fee equal to .25% of
                    the amount of proposed Term Loan, which shall be not be
                    refundable and shall in addition to all interest and to all
                    other amounts payable hereunder;

                    (f)  Borrower's execution and delivery of such additional
                    documents and Borrower's taking such additional actions as
                    Silicon determines are necessary or desirable in its
                    discretion; and

                    (g)  No Event of Default is then occurring or would
                    otherwise arise as a result of the making of the Term Loan.

INTEREST RATE
(Section 1.2):      Accounts Loans:  A rate equal to the "Prime Rate" in effect
                    --------------                                             
                    from time to time, plus 2.00% per annum, provided that on
                                                             --------        
                    and after such time after the date hereof that Borrower
                    incurs no losses (after taxes) in two consecutive fiscal
                    quarters, the rate shall be equal to "Prime Rate" in effect
                    from time to time, plus 1.50% per annum.

                    Term Loans:  A rate equal to the "Prime Rate" in effect from
                    ----------                                                  
                    time to time, plus 2.0% per annum.

                    Interest shall be calculated on the basis of a 360-day year
                    for the actual number of days elapsed.  "Prime Rate" means
                    the rate announced from time to time by Silicon as its
                    "prime rate;" it is a base rate upon which other rates
                    charged by Silicon are based, and it is not necessarily the
                    best rate available at Silicon.  The interest rate
                    applicable to the Obligations shall change on each date
                    there is a change in the Prime Rate.

LOAN ORIGINATION FEE
(Section 1.3):      SEE AMENDMENT OF EVEN DATE.  (Any Commitment Fee previously
                    paid by the Borrower in connection with this loan shall be
                    credited against this Fee.)

LETTER OF CREDIT SUBLIMIT
(Section 1.4):      $500,000

MATURITY DATE
(Section 5.1):      JULY 15, 1997, PROVIDED THAT THE MATURITY DATES REGARDING
                                   --------                                  
                    THE TERM LOANS, IF ANY, ARE AS SET FORTH IN SECTION 1.1
                    ABOVE.

                                      -3-
<PAGE>
 
Silicon Valley Bank                      Schedule to Loan and Security Agreement
--------------------------------------------------------------------------------

SUBSIDIARIES OF BORROWER
(Section 3.1):      NONE

PRIOR NAMES OF BORROWER
(Section 3.2):      NONE

PRESENT TRADE NAMES OF BORROWER
(Section 3.2):      NONE

PRIOR TRADE NAMES OF BORROWER
(Section 3.2):      NONE

OTHER LOCATIONS AND ADDRESSES
(Section 3.3):      NONE

MATERIAL ADVERSE LITIGATION
(Section 3.10):     NONE

NEGATIVE COVENANTS-EXCEPTIONS
(Section 4.6):      Without Silicon's prior written consent, Borrower may do the
                    following, provided that, after giving effect thereto, no
                    Event of Default has occurred and no event has occurred
                    which, with notice or passage of time or both, would
                    constitute an Event of Default, and provided that the
                    following are done in compliance with all applicable laws,
                    rules and regulations:  (i) repurchase shares of Borrower's
                    stock pursuant to any employee stock purchase or benefit
                    plan, provided that the total amount paid by Borrower for
                    such stock does not exceed $100,000 in any fiscal year and
                    (ii) make loans to, or guaranties of indebtedness of,
                    employees in an aggregate amount outstanding for such loans
                    and guaranties not to exceed $50,000 at any one time.

FINANCIAL COVENANTS
(Section 4.1):      Borrower shall comply with all of the following covenants.
                    Compliance shall be determined as of the end of each month,
                    except as otherwise specifically provided below:

  QUICK ASSET   
  RATIO:            Borrower shall maintain a ratio of "Quick Assets" to current
                    liabilities of not less than .60 to 1 starting with the
                    month ending June 30, 1996 through and including the month
                    ending September 30, 1996; thereafter, Borrower shall
                    maintain a ratio of "Quick Assets" to current liabilities of
                    not less than 1.50 to 1.

  CURRENT RATIO:    Borrower shall maintain a ratio of current assets to current
                    liabilities of not less than 1.25 to 1 starting with the
                    month ending June 30, 1996 through and including the month
                    ending September 30, 1996; thereafter, Borrower shall
                    maintain a ratio of current assets to current liabilities of
                    not less than 2.00 to 1.

  TANGIBLE NET 
  WORTH:            Borrower shall maintain a tangible net worth of not less
                    than $3,300,000 starting with the month ending June 30, 1996
                    through and including the month ending September 30, 1996;
                    thereafter, Borrower shall maintain a tangible net worth of
                    not less than $13,000,000.

  DEBT TO TANGIBLE 
  NET WORTH RATIO:  Borrower shall maintain a ratio of total liabilities to
                    tangible net worth of not more than 2.50 to 1 starting with
                    the month ending June 30, 1996 through and including the
                    month ending September 30, 1996; thereafter, Borrower shall
                    maintain a ratio of total liabilities to tangible net worth
                    of not more than .80 to 1.

                                      -4-
<PAGE>
 
PROFITABILITY       Beginning with the fiscal quarter ending September 30, 1996,
                    Borrower shall not incur a loss (after taxes) for any fiscal
                    quarter during the term hereof other than for a single
                    fiscal quarter after September 30, 1996 during the term
                    hereof, in which quarter Borrower may incur a one-time loss
                    (after taxes) in an amount not to exceed $800,000.

DEBT SERVICE 
RATIO/LIQUIDITY 
RATIO               Borrower shall either maintain the Debt Service Ratio as set
                                   ------
                    forth below or the Liquidity Ratio as set forth below at all
                    times that the Term Loan is outstanding:

                    Debt Service Ratio: Borrower shall maintain a quarterly Debt
                    ------------------
                    Service Ratio (as referred to below) relating to the
                    immediately preceding two fiscal quarters of not less than
                    1.50 to 1.

                    Liquidity Coverage Ratio: Borrower shall maintain a
                    ------------------------
                    Liquidity Coverage Ratio of 2.0 to 1 on a monthly basis.

DEFINITIONS:        "Current assets," and "current liabilities" shall have the
                    meanings ascribed to them in accordance with generally
                    accepted accounting principles.

                    "Tangible net worth" means the excess of total assets over
                    total liabilities, determined in accordance with generally
                    accepted accounting principles, excluding however all assets
                    which would be classified as intangible assets under
                    generally accepted accounting principles, including without
                    limitation goodwill, licenses, patents, trademarks, trade
                    names, copyrights, capitalized software and organizational
                    costs, licenses and franchises.

                    "Quick Assets" means cash on hand or on deposit in banks,
                    readily marketable securities issued by the United States,
                    readily marketable commercial paper rated "A-1" by Standard
                    & Poor's Corporation (or a similar rating by a similar
                    rating organization), certificates of deposit and banker's
                    acceptances, and accounts receivable (net of allowance for
                    doubtful accounts).

                    "Liquidity Quick Assets" means cash on hand or on deposit in
                    banks, readily marketable securities issued by the United
                    States, readily marketable commercial paper rated "A-1" by
                    Standard & Poor's Corporation (or a similar rating by a
                    similar rating organization), certificates of deposit and
                    banker's acceptances, plus 50% of the Borrower's accounts
                                          ----
                    eligible for borrowing pursuant to the terms and conditions
                    of this Agreement minus the aggregate amount of the Loans
                                      -----
                    and Letters of Credit outstanding.

                    "Debt Service Ratio" means the ratio of (a) net income of
                    Borrower before interest, taxes, depreciation and other non-
                    cash amortization expenses and other non-cash expenses of
                    the Borrower, determined in accordance with generally
                    accepted accounting principles, consistently applied, to (b)
                    the amount of Borrower's obligations relating to payment of
                    interest and current maturities of principal on Borrower's
                    outstanding long term indebtedness, determined in accordance
                    with generally accepted accounting principles, consistently
                    applied.

                                      -5-
<PAGE>
 
Silicon Valley Bank                      Schedule to Loan and Security Agreement
--------------------------------------------------------------------------------

                    "Liquidity Coverage Ratio" means the ratio of (a) Liquidity
                    Quick Assets to (b) the aggregate amount of Borrower's
                    obligations relating to the Term Loan.

  DEFERRED 
  REVENUES:         For purposes of the above quick asset ratio, deferred
                    revenues shall not be counted as current liabilities. For
                    purposes of the above debt to tangible net worth ratio,
                    deferred revenues shall not be counted in determining total
                    liabilities but shall be counted in determining tangible net
                    worth for purposes of such ratio. For all other purposes
                    deferred revenues shall be counted as liabilities in
                    accordance with generally accepted accounting principles,
                    consistently applied.

  SUBORDINATED 
  DEBT:             "Liabilities" for purposes of the foregoing covenants do not
                    include indebtedness which is subordinated to the
                    indebtedness to Silicon under a subordination agreement in
                    form specified by Silicon or by language in the instrument
                    evidencing the indebtedness which is acceptable to Silicon.

OTHER COVENANTS
(Section 4.1):      Borrower shall at all times comply with all of the following
                    additional covenants:

                    1.  BANKING RELATIONSHIP. Borrower shall at all times
                    maintain its primary banking relationship with Silicon.

                    2.  MONTHLY BORROWING BASE CERTIFICATE AND LISTING. Within
                    20 days after the end of each month, Borrower shall provide
                    Silicon with a Borrowing Base Certificate in such form as
                    Silicon shall specify, and an aged listing of Borrower's
                    accounts receivable and accounts payable.

                    3.  PRIOR WARRANTS; ADDITIONAL, NEW WARRANTS.  The Borrower
                    shall maintain in full force and effect the five-year
                    warrants to purchase 30,000 shares of Class A Common stock
                    of the Borrower, at $9.875 per share, on the terms and
                    conditions of the Warrant to Purchase Stock and related
                    documents executed and delivered in connection with the
                    original Loan Agreement.  Additionally, in connection with
                    the execution of the Amendment to Loan Agreement of even
                    date herewith, the Borrower shall provide Silicon with a
                    second set of five-year warrants to purchase 30,000 shares
                    of Class A Common stock of the Borrower, at $11.44 per
                    share, on the terms and conditions in the Warrant to
                    Purchase Stock and related documents being executed
                    concurrently with this Agreement.

                    4.  INDEBTEDNESS. Without limiting any of the foregoing
                    terms or provisions of this Agreement, Borrower shall not in
                    the future incur indebtedness for borrowed money, except for
                    (i) indebtedness to Silicon, and (ii) indebtedness incurred
                    in the future for the purchase price of or lease of
                    equipment in an aggregate amount not exceeding $250,000 at
                    any time outstanding.

                    5.  DAILY COLLATERAL CONTROL. Borrower shall provide to
                    Silicon transaction reports with respect to all of
                    Borrower's sales, receipts and other transactions as
                    specified from time to time by Silicon, copies of Borrower's
                    sales and collection journals, and such other information,
                    in such detail and with such frequency as Silicon shall from
                    time to time specify. Borrower shall have the privilege of
                    collecting Borrower's "accounts" (as defined in the
                    California Uniform Commercial Code) in trust for Silicon, at
                    Borrower's sole expense, which privilege may be revoked by
                    Silicon at any time. All proceeds 

                                      -6-
<PAGE>
 
Silicon Valley Bank                      Schedule to Loan and Security Agreement
--------------------------------------------------------------------------------

                    of all of Borrower's accounts, of every kind, in whatever
                    form received, shall be held by the Borrower in trust for
                    Silicon and shall be either (i) delivered by the Borrower to
                    Silicon in kind, in the same form as received, with any
                    necessary endorsements, within one business day after
                    receipt, or (ii) within one business day after receipt,
                    deposited to a bank account previously identified to
                    Silicon, which has been established pursuant to a written
                    agreement with Silicon which provides that all funds in such
                    account will be transferred to Silicon on a daily basis, and
                    in that event the Borrower shall deliver copies of all
                    checks and other proceeds so deposited and a copy of the
                    deposit receipt to Silicon within one business day after
                    such deposit. Borrower shall have no right to, and agrees
                    not to, commingle any of the proceeds of the accounts with
                    the Borrower's own funds, and the Borrower agrees not to
                    use, divert or withhold any such proceeds. The Borrower
                    will, upon request by Silicon and in such form and at such
                    times as Silicon shall request, give notice to the account
                    debtors on the accounts of the assignment of, and the grant
                    of a security interest in, the accounts to Silicon and
                    Silicon may itself give such notice at any time, without
                    notice to the Borrower, requiring such account debtors to
                    pay the accounts directly to Silicon, and in any such event,
                    the Borrower's privilege of collecting the accounts shall
                    automatically be deemed revoked.

                    6.  COLLATERAL CONTROL MONTHLY FEE. In addition to all other
                    amounts payable by Borrower hereunder, Borrower shall pay to
                    Silicon a Collateral Control Fee in the amount of $1,000 per
                    month.

                    BORROWER:

                        NETVANTAGE, INC.



                        By /s/ Stephen R. Rizzone
                          -------------------------------
                           President or Vice President



                        By /s/ Thomas V. Baker
                          -------------------------------
                           Secretary or Ass't Secretary


                    SILICON:

                        SILICON VALLEY BANK



                        By /s/ [SIGNATURE APPEARS HERE]
                          -------------------------------
                           Title Vice President
<PAGE>
 

                              Silicon Valley Bank

                         REGISTRATION RIGHTS AGREEMENT

     ISSUER:   NETVANTAGE, INC.

     ADDRESS:  201 CONTINENTAL BOULEVARD, SUITE 201
               EL SEGUNDO, CALIFORNIA 90245-4427

     DATE:


THIS REGISTRATION RIGHTS AGREEMENT is entered into as of the above date by and
between SILICON VALLEY BANK ("Purchaser"), whose address is 3003 Tasman Drive,
Santa Clara, California 95054 and the above Company, whose address is set forth
above.


                                    RECITALS


     A. Concurrently with the execution of this Agreement, the Purchaser is
purchasing from the Company a Warrant to Purchase Stock (the "Warrant") pursuant
to which Purchaser has the right to acquire from the Company the Shares (as
defined in the Warrant).

     B. By this Agreement, Purchaser and the Company desire to set forth the
registration rights of the Shares, all as provided herein.

NOW, THEREFORE, in consideration of the mutual promises, covenants and
conditions hereinafter set forth, the parties hereto mutually agree as follows:

1.   REGISTRATION RIGHTS. The Company, and the Purchaser with respect to
     -------------------                                                
Sections 1.6 and 2, covenant and agree as follows:

     1.1 Certain Definitions. As used in this Exhibit B the following terms
         -------------------                                               
shall have the following respective meanings:

          "Commission" shall mean the Securities and Exchange Commission or any
other federal agency at the time administering the Securities Act.

          "Common" shall mean any shares of any class of common stock of the
Company.

                                      -1-
<PAGE>
 
          "Exchange Act" shall mean the Securities Exchange Act of 1934, as
amended, or any similar federal statute, and the rules and regulations of the
Commission thereunder, all as the same shall be in effect at the time.

          "Founding Shareholder" shall mean any person who holds, or who
controls an entity that holds, irrespective of any escrow provision or
redemption or repurchase rights of the Company, at least two percent (2%) of the
Company's outstanding Common (assuming conversion of all outstanding preferred
stock or Class B and Class E Common).

          "Holder" shall mean (i) any Purchaser to the extent such Purchaser
holds Shares or Registrable Securities and (ii) any Permitted Transferee holding
Shares or Registrable Securities.

          "Permitted Transferees" shall mean any party to whom Each Purchaser
may transfer stock pursuant the Sections 4.2 and 4.3 of the Warrant without a
registration or opinion of counsel if such transferee expressly assumes the
obligations of a Purchaser under this Agreement.

          The terms "register," "registered," and "registration" refer to a
registration effected by preparing and filing a registration statement in
compliance with the Securities Act, and the declaration or ordering of the
effectiveness of such registration statement.

          "Registrable Securities" means the Shares, or shares issued as a
dividend or other distribution with respect to, or in exchange or in replacement
of, the Shares held by a Holder, excluding, however any Shares sold in a
transaction pursuant to a registration statement or pursuant to Rule 144.

          "Registration Expenses" shall mean all expenses incurred by the
Company in complying with Sections 1.2, 1.3 and 1.4 hereof, including, without
limitation, all registration and filing fees, printing expenses, fees and
disbursements of counsel for the Company, blue sky fees and expenses, and the
expense of any special audits incident to or required by any such registration
(but excluding the compensation of regular employees of the Company which shall
be paid in any event by the Company and Selling Expenses).

          "Securities Act" shall mean the Securities Act of 1933, as amended, or
any similar Federal Statute, and the rules and regulations of the Commission
thereunder, all as the same shall be in effect at the time.

          "Selling Expenses" shall mean all underwriting discounts and selling
commissions applicable to the sale.

                                      -2-
<PAGE>
 
     1.2  Right to Registration. If at any time or from time to time, the
          ---------------------                                          
Company shall determine to register any Common for its own account or for the
account of others, other than a registration relating solely to employee benefit
plans or a registration relating solely to a Commission Rule 145 transaction or
a registration on any registration form which does not include substantially the
same information as would be required to be included in a registration statement
covering the sale of Registrable Securities, the Company will:

          (a)  promptly give to all Holders and Founding Shareholders written
notice thereof (which shall include a list of the jurisdictions in which the
Company intends to attempt to qualify such securities under the applicable blue
sky or other state securities laws); and

          (b)  include in such registration (and any related qualification under
blue sky laws or other compliance), and in any underwriting involved therein,
all of the Registrable Securities specified in a written request by a Holder and
all shares of Common specified in a written request or requests by Founding
Shareholders, provided such written requests are received by the Company within
twenty (20) days following receipt by such Holders and Founding Shareholders of
such notice from the Company.

     1.3  Underwriting. If the registration of which the Company gives notice is
          ------------                                                          
for a registered public offering involving an underwriting, the Company shall so
advise the Holders and Founding Shareholders in the written notice given
pursuant to paragraph 1.2(a). In such event, the right of any Holder and
Founding Shareholder to registration pursuant to Section 1.2 shall be
conditioned upon such party's participation in such underwriting and the
inclusion of such party's Registrable Securities and such Founding Shareholder's
Common in the underwriting to the extent provided herein.  All parties proposing
to distribute their securities through such underwriting shall (together with
the Company and the other holders distributing their securities through such
underwriting) enter into an underwriting agreement in the customary form with
the underwriter or underwriters selected for such underwriting by the Company.
Notwithstanding any other provision of Section 1.2, if the Company and the
underwriter or underwriters determine that marketing factors require a
limitation of the number of shares to be underwritten, the underwriter may
exclude from such underwriting all or some of the shares proposed for
registration on behalf of Holders, Founding Shareholders, and other holders of
Company securities, on the following basis:

          (a) shares held by any person who does not have contractual rights to
cause the Company to register such shares shall first be excluded;

          (b) if further reductions are required, the shares that Founding
Shareholders have requested to be registered will next be excluded, such
reductions to be allocated as nearly as practicable based on the pro rata share
of the number of shares requested by all Founding Shareholder to be registered;
and

                                      -3-
<PAGE>
 
          (c) if further reductions are required, Registrable Securities will
next be excluded, such reductions to be allocated as nearly as practicable among
Holders in proportion to the number of shares that such Holder requests to be
registered hereunder bears to the total number of shares that all Holders
request to be registered, unless all such Holders shall otherwise unanimously
agree and advise the Company in writing.

          No shares excluded from the underwriting by reason of the
underwriter's marketing limitation shall be included in such registration. If
any Holder or Founding Shareholder disapproves of the terms of any such
underwriting, such person may elect to withdraw therefrom by written notice to
the Company and the underwriter. The Registrable Securities and/or other
securities so withdrawn from such underwriting shall also be withdrawn from such
registration; provided, however, that, if by the withdrawal of such shares a
greater number of Registrable Securities held by other Holders may be included
in such registration (up to the maximum of any limitation imposed by the
underwriters), then the Company shall offer to all Holders who have included
Registrable Securities in the registration the right to include additional
Registrable Securities in the same proportion used above in determining the
underwriter limitation.

     1.4  Preparation and Filing. In the case of each registration,
          ----------------------                                   
qualification, or compliance effected by the Company pursuant to this Exhibit B,
the Company will keep each Holder advised in writing as to the initiation of
each registration, qualification, and compliance and as to the completion
thereof. At its expense the Company will:

          (a) Keep such registration, qualification, or compliance effective for
a period of one hundred twenty (120) days or until the Holder or Holders have
completed the distribution described in the registration statement relating
thereto, whichever first occurs.

          (b) Prepare and file with the Commission such amendments and
supplements to such registration statement and the prospectus used in connection
with such registration statement as may be necessary to comply with the
provisions of the Securities Act with respect to the disposition of all
securities covered by such registration statement.

          (c) In the event of any underwritten public offering, enter into and
perform its obligations under an underwriting agreement, in the usual and
customary form, with the managing underwriter of such offering. Each Holder
participating in such underwriting shall also enter into and perform its
obligations under such an agreement.

          (d) Notify each Holder of Registrable Securities covered by such
registration statement at any time when a prospectus relating thereto is
required to be delivered under the Securities Act of the happening of any event
as a result of which 

                                      -4-
<PAGE>
 
the prospectus included in such registration statement, as then in effect,
includes an untrue statement of a material fact or omits to state a material
fact required to be stated therein or necessary to make the statements therein
not misleading in light of the circumstances then existing.

          (e) Furnish, at the request of any Holder requesting registration of
Registrable Securities pursuant to this Exhibit B, on the date that such
Registrable Securities are delivered to the underwriters for sale in connection
with said registration, if such securities are being sold through underwriters,
or the date that the registration statement with respect to such securities
becomes effective, (i) an opinion, dated as of such date, of the counsel
representing the Company for the purposes of such registration, in form and
substance as is customarily given to underwriters in an underwritten public
offering, addressed to the underwriters, if any, and to the Holders requesting
registration of Registrable Securities and (ii) a letter dated as of such date,
from the independent accountants of the Company, in form and substance as is
customarily given by independent accountants to underwriters in an underwritten
public offering, addressed to the underwriters, if any, and to the Holders
requesting registration of Registrable Securities.

     1.5   Expenses of Registration. All Registration Expenses incurred in
           ------------------------                                       
connection with any registration under this Exhibit B shall be borne by the
Company; and all Selling Expenses shall be borne by the holders of the
securities so registered pro rata on the basis of the number of shares so
registered.

     1.6  Indemnification.
          --------------- 

          (a) The Company shall indemnify each Holder (which term, for purposes
of this Section 1.6, shall be deemed to include Founding Shareholders who
include shares in a registration) participating in any registration,
qualification, or compliance effected pursuant to this Exhibit B with respect to
Registrable Securities held by such Holder, each of its officers, directors,
partners, controlling persons and legal counsel, and each underwriter, if any,
and each person who controls any underwriter, against all claims, losses,
damages, and liabilities (or actions in respect thereof), including any of the
foregoing incurred in settlement of any litigation, commenced or threatened, to
which they may become subject under the Securities Act, the Exchange Act, or
other federal or state law, arising out of or based on (i) any untrue statement
(or alleged untrue statement) of a material fact contained in any prospectus,
offering circular or other similar document incident to any such registration,
qualification or compliance, or based on any omission (or alleged omission) to
state therein a material fact required to be stated therein or necessary to make
the statements therein not misleading in light of the circumstances under which
they were made, or (ii) any violation by the Company of any federal, state, or
common law rule or regulation applicable to the Company in connection with any
such registration, qualification or compliance, and will reimburse each such
Holder, each of its officers, directors, partners, controlling persons and legal
counsel, each such underwriter, and each person who controls any 

                                      -5-
<PAGE>
 
such underwriter, for any legal and any other expenses reasonably incurred in
connection with investigating and/or defending any such claim, loss, damage,
liability, or action, as incurred, provided that the Company will not be liable
in any case to the extent that any such claim, loss, damage, liability or
expense arises out of or is based on any untrue statement or omission, made in
reliance on and in conformity with written information furnished to the Company
by a Holder or underwriter specifically for use therein.

          (b) Each Holder will, if Registrable Securities held by such Holder
are included in the securities as to which such registration, qualification or
compliance is being effected, indemnify the Company, each of its officers,
directors, partners, controlling persons and legal counsel, each underwriter, if
any, of the Company's securities covered by such registration statement, each
person who controls such underwriter, and each other Holder, each of its
officers, directors, controlling person and partners, against all claims,
losses, damages and liabilities (or actions in respect thereof) arising out of
or based on any untrue statement (or alleged untrue statement) of a material
fact contained in any such registration statement, prospectus, offering
circular, or other similar document, or any omission (or alleged omission) to
state therein a material fact required to be stated therein or necessary to make
the statements therein not misleading in light of the circumstances under which
they were made, and will reimburse the Company, such other Holders, such
directors, officers, persons, underwriters, controlling persons or legal counsel
for any legal or any other expenses reasonably incurred in connection with
investigating and/or defending any such claim, loss, damage, liability, or
action, as incurred, in each case to the extent, but only to the extent, that
such untrue statement (or alleged untrue statement) or omission (or alleged
omission) is made in such registration statement, prospectus, offering circular,
or other document in reliance upon and in conformity with written information
furnished to the Company by such Holder specifically for use therein.
Notwithstanding anything herein to the contrary, the total amount for which any
Holder shall be liable under this subsection 1.6(b) shall not exceed the
aggregate proceeds received by such Holder from the sale of Registrable
Securities held by such Holder in such registration.

          (c) Each party entitled to indemnification under this Section 1.6 (the
"Indemnified Party") shall give notice to the party required to provide such
indemnification (the "Indemnifying Party") promptly after such Indemnified Party
has received written notice of any claim as to which indemnity may be sought,
and shall permit the Indemnifying Party to assume the defense of any such claim
or any litigation resulting therefrom, provided that counsel for the
Indemnifying Party who shall conduct the defense of such claim or litigation,
shall be approved by the Indemnified Party (whose approval shall not
unreasonably be withheld). The Indemnified Party may participate in such defense
at its own expense. The failure of any Indemnified Party to give notice as
provided herein shall relieve the Indemnifying Party of its obligations under
this Section 1.6 only to the extent that such failure to give notice shall
materially adversely prejudice the Indemnifying Party in the defense of any such

                                      -6-
<PAGE>
 
claim or any such litigation. No Indemnifying Party, in the defense of any such
claim or litigation, shall, except with the consent of each Indemnified Party,
consent to entry of any judgment or enter into any settlement that does not
include as an unconditional term thereof the giving by the claimant or plaintiff
to such Indemnified Party of a release from all liability in respect to such
claim or litigation.


     1.7  Information by Holder. The Holders of Registrable Securities included
          ---------------------                                                
in any registration shall furnish to the Company such information regarding such
Holder or Holders and the distribution proposed by such Holder or Holders as the
Company may request in writing and as shall be required in connection with any
registration, qualification, or compliance referred to in this Exhibit B.

     1.8  Limited Transfer of Registration Rights. The rights granted under this
          ---------------------------------------                               
Exhibit B may not be assigned or otherwise conveyed except to a Permitted
Transferee; and only if the Company is promptly given written notice, signed by
the transferor and transferee, setting forth such transferee's name and address
and said transferee's agreement to be bound by the provisions of this Agreement.

     1.9  Market Stand-off Agreement. Each Holder agrees that in connection with
          --------------------------                                            
any registration of the Company's securities, that upon the request of the
Company or any underwriter managing an underwritten offering of the Company's
securities, that said Holder shall not sell, short any sale of, loan, grant an
option for, or otherwise dispose of any of the Registrable Securities, other
than those included in the offering, without the prior written consent of the
Company or such managing underwriter, as applicable, for a period of at least
120 days following the effective date of registration of such offering, provided
that all officers of the Company have also entered into similar agreements. The
Company shall have the right to impose "stop transfer" instructions during such
120 day period with respect to any securities subject to the foregoing
restriction.

2. GENERAL.
   ------- 


     2.l  Waivers and Amendments.  With the written consent of the record or
          ----------------------                                            
beneficial holders of at least a majority of the Registrable Securities, the
obligations of the Company and the rights of the Holders of the Registrable
Securities under this agreement may be waived (either generally or in a
particular instance, either retroactively or prospectively, and either for a
specified period of time or indefinitely), and with the same consent the
Company, when authorized by resolution of its Board of Directors, may enter into
a supplementary agreement for the purpose of adding any provisions to or
changing in any manner or eliminating any of the provisions of this Agreement;
provided, however, that no such modification, amendment or waiver shall reduce
the aforesaid percentage of Registrable Securities. Upon the effectuation of
each such waiver, consent, agreement of amendment or modification, the Company
shall promptly give written notice thereof to the record holders of the
Registrable Securities who have not previously consented thereto in writing.
This Agreement or any provision hereof may be changed, 

                                      -7-
<PAGE>
 
waived, discharged or terminated only by a statement in writing signed by the
party against which enforcement of the change, waiver, discharge or termination
is sought, except to the extent provided in this subsection 2.1.

     2.2  Governing Law. This Agreement shall be governed in all respects by the
          -------------                                                         
laws of the State of California as such laws are applied to agreements between
California residents entered into and to be performed entirely within
California.

     2.3  Successors and Assigns. Except as otherwise expressly provided herein,
          ----------------------                                                
the provisions hereof shall inure to the benefit of, and be binding upon, the
successors, assigns, heirs, executors and administrators of the parties hereto.

     2.4  Entire Agreement. Except as set forth below, this Agreement and the
          ----------------                                                   
other documents delivered pursuant hereto constitute the full and entire
understanding and agreement between the parties with regard to the subjects
hereof and thereof.

     2.5  Notices, etc. All notices and other communications required or
          ------------                                                  
permitted hereunder shall be in writing and shall be mailed by first class mail,
postage prepaid, certified or registered mail, return receipt requested,
addressed (a) if to Holder, at such Holder's address as set forth in the heading
to this Agreement, or at such other address as such Holder shall have furnished
to the Company in writing, or (b) if to the Company, at the Company's address
set forth in the heading to this Agreement, or at such other address as the
Company shall have furnished to the Holder in writing.

     2.6  Severability. In case any provision of this Agreement shall be
          ------------                                                  
invalid, illegal, or unenforceable, the validity, legality and enforceability of
the remaining provisions of this Agreement or any provision of the other
Agreements shall not in any way be affected or impaired thereby.

     2.7  Titles and Subtitles. The titles of the sections and subsections of
          --------------------                                               
this Agreement are for convenience of reference only and are not to be
considered in construing this Agreement.

                                      -8-
<PAGE>
 
     2.8  Counterparts. This Agreement may be executed in any number of
          ------------                                                 
counterparts, each of which shall be an original, but all of which together
shall constitute one instrument.

Company:

     NETVANTAGE, INC.


     By:  /s/ Stephen R. Rizzone
        ----------------------------------
           President or Vice President



     By:  /s/ Thomas V. Baker
        ----------------------------------
           Secretary or Ass't Secretary


Purchaser:

     SILICON VALLEY BANK


     By:  /s/ [SIGNATURE APPEARS HERE]
        ----------------------------------
     Title: Sr. Vice President
            ------------------------------
                                      -9-
<PAGE>
 

THIS WARRANT AND THE SHARES ISSUABLE HEREUNDER HAVE NOT BEEN REGISTERED UNDER
THE SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT BE SOLD, PLEDGED, OR
OTHERWISE TRANSFERRED WITHOUT AN EFFECTIVE REGISTRATION THEREOF UNDER SUCH ACT
OR PURSUANT TO RULE 144 OR AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE
CORPORATION AND ITS COUNSEL, THAT SUCH REGISTRATION IS NOT REQUIRED.

                  -------------------------------------------


                           WARRANT TO PURCHASE STOCK

WARRANT TO PURCHASE 30,000            ISSUE DATE:  JULY 15, 1996
SHARES OF THE CLASS A COMMON          EXPIRATION DATE:  JULY 15, 2001
STOCK OF NETVANTAGE, INC.             INITIAL EXERCISE PRICE:  $9.875 PER SHARE
 

THIS WARRANT CERTIFIES THAT, for the agreed upon value of $1.00 and for other
good and valuable consideration, SILICON VALLEY BANK ("Holder") is entitled to
purchase the number of fully paid and non-assessable shares of the class of
securities (the "Shares") of the corporation (the "Company") at the initial
exercise price per Share (the "Warrant Price") all as set forth above and as
adjusted pursuant to Article 2 of this Warrant, subject to the provisions and
upon the terms and conditions set forth in this Warrant.

ARTICLE 1.  EXERCISE.

          1.1      METHOD OF EXERCISE.  Holder may exercise this Warrant by
delivering a duly executed Notice of Exercise in substantially the form attached
as Appendix 1 to the principal office of the Company.  Unless Holder is
exercising the conversion right set forth in Section 1.2, Holder shall also
deliver to the Company a check for the aggregate Warrant Price for the Shares
being purchased.

          1.2      CONVERSION RIGHT.  In lieu of exercising this Warrant as
specified in Section 1.1, Holder may from time to time convert this Warrant, in
whole or in part, into a number of Shares determined by dividing (a) the
aggregate fair market value of the Shares or other securities otherwise issuable
upon exercise of this Warrant minus the aggregate Warrant Price of such Shares
by (b) the fair market value of one Share.  The fair market value of the Shares
shall be determined pursuant Section 1.4.

          1.3      [ALTERNATIVE STOCK APPRECIATION RIGHT.  At Holder's option,
the Company shall pay Holder the fair market value of the Shares issuable upon
conversion of this Warrant pursuant to Section 1.2 in cash in lieu of such
Shares.]

          1.4      FAIR MARKET VALUE.  If the Shares are traded in a public
market, the fair market value of the Shares shall be * [the closing price of the
Shares (or the closing price of the Company's stock into which the Shares are
convertible) reported for the business day immediately before Holder delivers
its Notice of Exercise to the Company.] If the Shares are not ** traded in a
public market, the Board of Directors of the Company shall determine fair market
value in its reasonable good faith judgment. The foregoing notwithstanding, if
Holder advises the Board of Directors in writing that Holder disagrees with such
determination, then the Company and Holder shall promptly agree upon a reputable
investment banking firm to undertake such valuation. If the valuation of such
investment banking firm is greater than that determined by the Board of
Directors, then all fees and expenses of such investment banking firm shall be
paid by the Company. In all other circumstances, such fees and expenses shall be
paid by Holder.

          * THE AVERAGE OF THE CLOSING PRICE OF SUCH STOCK ON THE NASDAQ
NATIONAL MARKET SYSTEM OR SMALL CAP ISSUE MARKET, AS APPLICABLE, FOR THE TEN
TRADING DAYS IMMEDIATELY PRECEDING THE DATE OF RECEIPT BY THE COMPANY OF THE
NOTICE OF EXERCISE

          ** NO LONGER

          1.5      DELIVERY OF CERTIFICATE AND NEW WARRANT.  Promptly after
Holder exercises or converts this Warrant, the Company shall deliver to Holder
certificates for the Shares acquired and, if this Warrant has not been fully
exercised or converted and has not expired, a new Warrant representing the
Shares not so acquired.

          1.6      REPLACEMENT OF WARRANTS.  On receipt of evidence reasonably
satisfactory to the Company of the loss, theft, destruction or mutilation of
this Warrant and, in the case of loss, theft or destruction, on delivery of an
indemnity agreement reasonably satisfactory in form and amount to the Company
or, in the case of mutilation, or surrender and cancellation of this Warrant,
the Company at its expense shall execute and deliver, in lieu of this Warrant, a
new warrant of like tenor.

          1.7 REPURCHASE ON SALE, MERGER OR CONSOLIDATION OF THE COMPANY.

          1.7.1.   "ACQUISITION".  For the purpose of this Warrant,
"Acquisition" means any sale, license, or other disposition of all or
substantially all of the assets of the Company, or any reorganization,
consolidation, or merger of the Company where the holders of the Company's
securities before the transaction beneficially own less than 50% of the
outstanding voting securities of the surviving entity after the transaction.

          1.7.2.   ASSUMPTION OF WARRANT.  If upon the closing of any
Acquisition the successor entity assumes the 

NOTE TO EDGAR VERSION: Deleted language is indicated by brackets, not 
                       strike-throughs.

                                      -1-
<PAGE>
 
Silicon Valley Bank                                    Warrant to Purchase Stock
--------------------------------------------------------------------------------

obligations of this Warrant, then this Warrant shall be exercisable for the same
securities, cash, and property as would be payable for the Shares issuable upon
exercise of the unexercised portion of this Warrant as if such Shares were
outstanding on the record date for the Acquisition and subsequent closing. The
Warrant Price shall be adjusted accordingly.

          1.7.3.   NONASSUMPTION.  If upon the closing of any Acquisition the
successor entity does not assume the obligations of this Warrant and Holder has
not otherwise exercised this Warrant in full, then the unexercised portion of
this Warrant shall be deemed to have been automatically converted pursuant to
Section 1.2 and thereafter Holder shall participate in the acquisition on the
same terms as other holders of the same class of securities of the Company.

          1.7.4.   [PURCHASE RIGHT.  Notwithstanding the foregoing, at the
election of Holder, the Company shall purchase the unexercised portion of this
Warrant for cash upon the closing of any Acquisition for an amount equal to (a)
the fair market value of any consideration that would have been received by
Holder in consideration of the Shares had Holder exercised the unexercised
portion of this Warrant immediately before the record date for determining the
shareholders entitled to participate in the proceeds of the Acquisition, less
(b) the aggregate Warrant Price of the Shares, but in no event less than zero.]

ARTICLE 2.  ADJUSTMENTS TO THE SHARES.

          2.1      STOCK DIVIDENDS, SPLITS, ETC.  If the Company declares or
pays a dividend on its common stock (or the Shares if the Shares are securities
other than common stock) payable in common stock, or other securities,
subdivides the outstanding common stock into a greater amount of common stock,
or, if the Shares are securities other than common stock, subdivides the Shares
in a transaction that increases the amount of common stock into which the Shares
are convertible, then upon exercise of this Warrant, for each Share acquired,
Holder shall receive, without cost to Holder, the total number and kind of
securities to which Holder would have been entitled had Holder owned the Shares
of record as of the date the dividend or subdivision occurred.

          2.2      RECLASSIFICATION, EXCHANGE OR SUBSTITUTION.  Upon any
reclassification, exchange, substitution, or other event that results in a
change of the number and/or class of the securities issuable upon exercise or
conversion of this Warrant, Holder shall be entitled to receive, upon exercise
or conversion of this Warrant, the number and kind of securities and property
that Holder would have received for the Shares if this Warrant had been
exercised immediately before such reclassification, exchange, substitution, or
other event.  Such an event shall include any automatic conversion of the
outstanding or issuable securities of the Company of the same class or series as
the Shares to common stock pursuant to the terms of the Company's Articles of
Incorporation upon the closing of a registered public offering of the Company's
common stock.  The Company or its successor shall promptly issue to Holder a new
Warrant for such new securities or other property.  The new Warrant shall
provide for adjustments which shall be as nearly equivalent as may be
practicable to the adjustments provided for in this Article 2 including, without
limitation, adjustments to the Warrant Price and to the number of securities or
property issuable upon exercise of the new Warrant.  The provisions of this
Section 2.2 shall similarly apply to successive reclassifications, exchanges,
substitutions, or other events.

          2.3      ADJUSTMENTS FOR COMBINATIONS, ETC.  If the outstanding Shares
are combined or consolidated, by reclassification or otherwise, into a lesser
number of shares, the Warrant Price shall be proportionately increased.

          2.4      ADJUSTMENTS FOR ADDITIONAL ISSUANCES.  The number of Shares
issuable upon exercise of this Warrant shall be subject to adjustment, from time
to time, as set forth in this Section 2.4.  The term "Silicon Percentage
Interest" shall mean the ratio of the number of shares subject of this Warrant
as of the date hereof to the number of fully diluted shares of the Company as in
effect as of the date hereof.  At such time, and from time to time, that the
number of fully diluted shares of the Company increases, the number of shares
subject of this Warrant shall be considered increased by such an amount in order
to maintain in effect the Silicon Percentage Interest at all times with respect
to the number of shares subject of this Warrant as a ratio to the then increased
number of fully diluted shares, provided in no instance shall the number of
                                --------                                   
shares subject of this Warrant be reduced.

          As used herein the number of fully diluted shares means the aggregate
amount of all common stock (including reissued shares) issued (or deemed to be
issued as noted in the following sentences).  The shares of common stock
ultimately issuable upon exercise of an option (including the shares of common
stock ultimately issuable upon conversion or exercise of a convertible security
issuable pursuant to an option) are deemed to be issued when the option is
Issued.  The shares of common stock ultimately issuable upon conversion or
exercise of a convertible security (other than a convertible security issued
pursuant to an option) shall be deemed Issued upon issuance of the convertible
security.

          2.5      NO IMPAIRMENT.  The Company shall not, by amendment of its
Articles of Incorporation or through a reorganization, transfer of assets,
consolidation, merger, dissolution, issue, or sale of securities or any other
voluntary action, avoid or seek to avoid the observance or performance of any of
the terms to be observed or performed under this Warrant by the Company, but
shall at all times in good faith assist in carrying out of all the provisions of
this Article 2 and in taking all such action as may be necessary or appropriate
to protect Holder's rights under this Article against impairment.  If the
Company takes any action affecting the Shares or its common stock other than as
described above that adversely affects Holder's rights under this Warrant, the
Warrant Price shall be adjusted downward and the number of Shares issuable 

                                      -2-
<PAGE>
 
Silicon Valley Bank                                    Warrant to Purchase Stock
--------------------------------------------------------------------------------

upon exercise of this Warrant shall be adjusted upward in such a manner that the
aggregate Warrant Price of this Warrant is unchanged.

          2.6      FRACTIONAL SHARES.  No fractional Shares shall be issuable
upon exercise or conversion of the Warrant and the number of Shares to be issued
shall be rounded down to the nearest whole Share.  If a fractional share
interest arises upon any exercise or conversion of the Warrant, the Company
shall eliminate such fractional share interest by paying Holder amount computed
by multiplying the fractional interest by the fair market value of a full Share.

          2.7      CERTIFICATE AS TO ADJUSTMENTS.  Upon each adjustment of the
Warrant Price, the Company at its expense shall promptly compute such
adjustment, and furnish Holder with a certificate of its Chief Financial Officer
setting forth such adjustment and the facts upon which such adjustment is based.
The Company shall, upon written request, furnish Holder a certificate setting
forth the Warrant Price in effect upon the date thereof and the series of
adjustments leading to such Warrant Price.

ARTICLE 3.  REPRESENTATIONS AND COVENANTS OF THE COMPANY.

          3.1  REPRESENTATIONS AND WARRANTIES.  The Company hereby represents
and warrants to the Holder as follows:

          (a) The initial Warrant Price referenced on the first page of this
Warrant is not greater than (i) the price per share at which the Shares were
last issued in an arms-length transaction in which at least $500,000 of the
Shares were sold and (ii) the fair market value of the Shares as of the date of
this Warrant.

          (b) All Shares which may be issued upon the exercise of the purchase
right represented by this Warrant, and all securities, if any, issuable upon
conversion of the Shares, shall, upon issuance, be duly authorized, validly
issued, fully paid and non-assessable, and free of any liens and encumbrances
except for restrictions on transfer provided for herein or under applicable
federal and state securities laws.

          3.2      NOTICE OF CERTAIN EVENTS.  If the Company proposes at any
time (a) to declare any dividend or distribution upon its common stock, whether
in cash, property, stock, or other securities and whether or not a regular cash
dividend; (b) to offer for subscription pro rata to the holders of any class or
series of its stock any additional shares of stock of any class or series or
other rights; (c) to effect any reclassification or recapitalization of common
stock; (d) to merge or consolidate with or into any other corporation, or sell,
lease, license, or convey all or substantially all of its assets, or to
liquidate, dissolve or wind up; or (e) offer holders of registration rights the
opportunity to participate in an underwritten public offering of the company's
securities for cash, then, in connection with each such event, the Company shall
give Holder (1) at least 20 days prior written notice of the date on which a
record will be taken for such dividend, distribution, or subscription rights
(and specifying the date on which the holders of common stock will be entitled
thereto) or for determining rights to vote, if any, in respect of the matters
referred to in (c) and (d) above; (2) in the case of the matters referred to in
(c) and (d) above at least 20 days prior written notice of the date when the
same will take place (and specifying the date on which the holders of common
stock will be entitled to exchange their common stock for securities or other
property deliverable upon the occurrence of such event); and (3) in the case of
the matter referred to in (e) above, the same notice as is given to the holders
of such registration rights.

          3.3      INFORMATION RIGHTS.  So long as the Holder holds this Warrant
and/or any of the Shares, the Company shall deliver to the Holder (a) promptly
after mailing, copies of all notices or other written communications to the
shareholders of the Company, (b) within ninety (90) days after the end of each
fiscal year of the Company, the annual audited financial statements of the
Company certified by independent public accountants of recognized standing and
(c) within forty-five (45) days after the end of each of the first three
quarters of each fiscal year, the Company's quarterly, unaudited financial
statements.

          3.4      REGISTRATION UNDER SECURITIES ACT OF 1933, AS AMENDED.  The
Company agrees that the Shares or, if the Shares are convertible into common
stock of the Company, such common stock, shall be subject to the registration
rights set forth on Exhibit B, if attached.

ARTICLE 4.  MISCELLANEOUS.
            ------------- 

          4.1      TERM: NOTICE OF EXPIRATION.  This Warrant is exercisable, in
whole or in part, at any time and from time to time on or before the Expiration
Date set forth above.  The Company shall give Holder written notice of Holder's
right to exercise this Warrant in the form attached as Appendix 2 not more than
90 days and not less than 30 days before the Expiration Date. If the notice is
not so given, the Expiration Date shall automatically be extended until 30 days
after the date the Company delivers the notice to Holder.

          4.2      LEGENDS.  This Warrant and the Shares (and the securities
issuable, directly or indirectly, upon conversion of the Shares, if any) shall
be imprinted with a legend in substantially the following form:

          THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
1933, AS AMENDED, AND MAY NOT BE SOLD, PLEDGED OR OTHERWISE TRANSFERRED WITHOUT
AN EFFECTIVE REGISTRATION THEREOF UNDER SUCH ACT OR PURSUANT TO RULE 144 OR AN
OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE CORPORATION AND ITS COUNSEL
THAT SUCH REGISTRATION IS NOT REQUIRED.

          4.3      COMPLIANCE WITH SECURITIES LAWS ON TRANSFER.  This Warrant
and the Shares issuable upon exercise this Warrant (and the securities issuable,
directly or indirectly upon conversion of the Shares, if any) may not be
transferred or assigned in whole or in part without 

                                      -3-
<PAGE>
 
Silicon Valley Bank                                    Warrant to Purchase Stock
--------------------------------------------------------------------------------

compliance with applicable federal and state securities laws by the transferor
and the transferee (including, without limitation, the delivery of investment
representation letters and legal opinions reasonably satisfactory to the
Company, if reasonably requested by the Company). The Company shall not require
Holder to provide an opinion of counsel if the transfer is to an affiliate of
Holder or if there is no material question as to the availability of current
information as referenced in Rule 144(c), Holder represents that it has complied
with Rule 144(d) and (e) in reasonable detail, the selling broker represents
that it has complied with Rule 144(f), and the Company is provided with a copy
of Holders notice of proposed sale.

          4.4      TRANSFER PROCEDURE.  Subject to the provisions of Section 4.2
and Section 4.3, Holder may transfer all or part of this Warrant or the Shares
issuable upon exercise of this Warrant (or the securities issuable, directly or
indirectly, upon conversion of the Shares, if any) by giving the Company notice
of the portion of the Warrant being transferred setting forth the name, address
and taxpayer identification number of the transferee and surrendering this
Warrant to the Company for reissuance to the transferee(s) (and Holder if
applicable).  Unless the Company is filing financial information with the SEC
pursuant to the Securities Exchange Act of 1934, the Company shall have the
right to refuse to transfer any portion of this Warrant to any person who
directly competes with the Company.

          4.5      NOTICES.  All notices and other communications from the
Company to the Holder, or vice versa, shall be deemed delivered and effective
when given personally or mailed by first-class registered or certified mail,
postage prepaid, at such address as may have been furnished to the Company or
the Holder, as the case may be, in writing by the Company or such holder from
time to time.

          4.6      WAIVER.  This Warrant and any term hereof may be changed,
waived, discharged or terminated only by an instrument in writing signed by the
party against which enforcement of such change, waiver, discharge or termination
is sought.

          4.7      ATTORNEYS FEES.  In the event of any dispute between the
parties concerning the terms and provisions of this Warrant, the party
prevailing in such dispute shall be entitled to collect from the other party all
costs incurred in such dispute, including reasonable attorneys' fees.

          4.8      GOVERNING LAW.  This Warrant shall be governed by and
construed in accordance with the laws of the State of California, without giving
effect to its principles regarding conflicts of law.

                                       NETVANTAGE, INC.


                                       By /s/ Stephen R. Rizzone
                                         -----------------------------------
                                         Chairman of the Board, President or
                                         Vice President


                                       By /s/ Thomas V. Baker
                                         -----------------------------------
                                         Secretary or Ass't Secretary

                                      -4-
<PAGE>
 
THIS WARRANT AND THE SHARES ISSUABLE HEREUNDER HAVE NOT BEEN REGISTERED UNDER
THE SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT BE SOLD, PLEDGED, OR
OTHERWISE TRANSFERRED WITHOUT AN EFFECTIVE REGISTRATION THEREOF UNDER SUCH ACT
OR PURSUANT TO RULE 144 OR AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE
CORPORATION AND ITS COUNSEL, THAT SUCH REGISTRATION IS NOT REQUIRED.


                           -------------------------

                           WARRANT TO PURCHASE STOCK


WARRANT TO PURCHASE 30,000            ISSUE DATE:  AUGUST 16, 1996
SHARES OF THE CLASS A COMMON          EXPIRATION DATE:  AUGUST 16, 2001
STOCK OF NETVANTAGE, INC.             INITIAL EXERCISE PRICE:  $11.44 PER SHARE
 

THIS WARRANT CERTIFIES THAT, for the agreed upon value of $1.00 and for other
good and valuable consideration, SILICON VALLEY BANK ("Holder") is entitled to
purchase the number of fully paid and non-assessable shares of the class of
securities (the "Shares") of the corporation (the "Company") at the initial
exercise price per Share (the "Warrant Price") all as set forth above and as
adjusted pursuant to Article 2 of this Warrant, subject to the provisions and
upon the terms and conditions set forth in this Warrant.

ARTICLE 1.  EXERCISE.

          1.1      METHOD OF EXERCISE.  Holder may exercise this Warrant by
delivering a duly executed Notice of Exercise in substantially the form attached
as Appendix 1 to the principal office of the Company.  Unless Holder is
exercising the conversion right set forth in Section 1.2, Holder shall also
deliver to the Company a check for the aggregate Warrant Price for the Shares
being purchased.

          1.2      CONVERSION RIGHT.  In lieu of exercising this Warrant as
specified in Section 1.1, Holder may from time to time convert this Warrant, in
whole or in part, into a number of Shares determined by dividing (a) the
aggregate fair market value of the Shares or other securities otherwise issuable
upon exercise of this Warrant minus the aggregate Warrant Price of such Shares
by (b) the fair market value of one Share.  The fair market value of the Shares
shall be determined pursuant Section 1.4.

          1.3      [ALTERNATIVE STOCK APPRECIATION RIGHT.  At Holder's option,
the Company shall pay Holder the fair market value of the Shares issuable upon
conversion of this Warrant pursuant to Section 1.2 in cash in lieu of such
Shares.]

          1.4      FAIR MARKET VALUE.  If the Shares are traded in a public
market, the fair market value of the Shares shall be * [the closing price of the
Shares (or the closing price of the Company's stock into which the Shares are
convertible) reported for the business day immediately before Holder delivers
its Notice of Exercise to the Company.] If the Shares are [not] ** traded in a
public market, the Board of Directors of the Company shall determine fair market
value in its reasonable good faith judgment. The foregoing notwithstanding, if
Holder advises the Board of Directors in writing that Holder disagrees with such
determination, then the Company and Holder shall promptly agree upon a reputable
investment banking firm to undertake such valuation. If the valuation of such
investment banking firm is greater than that determined by the Board of
Directors, then all fees and expenses of such investment banking firm shall be
paid by the Company. In all other circumstances, such fees and expenses shall be
paid by Holder.

          * THE AVERAGE OF THE CLOSING PRICE OF SUCH STOCK ON THE NASDAQ
NATIONAL MARKET SYSTEM OR SMALL CAP ISSUE MARKET, AS APPLICABLE, FOR THE TEN
TRADING DAYS IMMEDIATELY PRECEDING THE DATE OF RECEIPT BY THE COMPANY OF THE
NOTICE OF EXERCISE

          ** NO LONGER

          1.5      DELIVERY OF CERTIFICATE AND NEW WARRANT.  Promptly after
Holder exercises or converts this Warrant, the Company shall deliver to Holder
certificates for the Shares acquired and, if this Warrant has not been fully
exercised or converted and has not expired, a new Warrant representing the
Shares not so acquired.

          1.6      REPLACEMENT OF WARRANTS.  On receipt of evidence reasonably
satisfactory to the Company of the loss, theft, destruction or mutilation of
this Warrant and, in the case of loss, theft or destruction, on delivery of an
indemnity agreement reasonably satisfactory in form and amount to the Company
or, in the case of mutilation, or surrender and cancellation of this Warrant,
the Company at its expense shall execute and deliver, in lieu of this Warrant, a
new warrant of like tenor.

          1.7 REPURCHASE ON SALE, MERGER OR CONSOLIDATION OF THE COMPANY.

          1.7.1.   "ACQUISITION".  For the purpose of this Warrant,
"Acquisition" means any sale, license, or other disposition of all or
substantially all of the assets of the Company, or any reorganization,
consolidation, or merger of the Company where the holders of the Company's
securities before the transaction beneficially own less than 50% of the
outstanding voting securities of the surviving entity after the transaction.

          1.7.2.   ASSUMPTION OF WARRANT.  If upon the closing of any
Acquisition the successor entity assumes the 


NOTE TO EDGAR VERSION:  Deleted language is indicated by brackets, not 
                        strike-throughs.

                                      -1-
<PAGE>
 
Silicon Valley Bank                                    Warrant to Purchase Stock
--------------------------------------------------------------------------------

obligations of this Warrant, then this Warrant shall be exercisable for the same
securities, cash, and property as would be payable for the Shares issuable upon
exercise of the unexercised portion of this Warrant as if such Shares were
outstanding on the record date for the Acquisition and subsequent closing. The
Warrant Price shall be adjusted accordingly.

          1.7.3.   NONASSUMPTION.  If upon the closing of any Acquisition the
successor entity does not assume the obligations of this Warrant and Holder has
not otherwise exercised this Warrant in full, then the unexercised portion of
this Warrant shall be deemed to have been automatically converted pursuant to
Section 1.2 and thereafter Holder shall participate in the acquisition on the
same terms as other holders of the same class of securities of the Company.

          1.7.4.   [PURCHASE RIGHT.  Notwithstanding the foregoing, at the
election of Holder, the Company shall purchase the unexercised portion of this
Warrant for cash upon the closing of any Acquisition for an amount equal to (a)
the fair market value of any consideration that would have been received by
Holder in consideration of the Shares had Holder exercised the unexercised
portion of this Warrant immediately before the record date for determining the
shareholders entitled to participate in the proceeds of the Acquisition, less
(b) the aggregate Warrant Price of the Shares, but in no event less than zero.]

ARTICLE 2.  ADJUSTMENTS TO THE SHARES.

          2.1      STOCK DIVIDENDS, SPLITS, ETC.  If the Company declares or
pays a dividend on its common stock (or the Shares if the Shares are securities
other than common stock) payable in common stock, or other securities,
subdivides the outstanding common stock into a greater amount of common stock,
or, if the Shares are securities other than common stock, subdivides the Shares
in a transaction that increases the amount of common stock into which the Shares
are convertible, then upon exercise of this Warrant, for each Share acquired,
Holder shall receive, without cost to Holder, the total number and kind of
securities to which Holder would have been entitled had Holder owned the Shares
of record as of the date the dividend or subdivision occurred.

          2.2      RECLASSIFICATION, EXCHANGE OR SUBSTITUTION.  Upon any
reclassification, exchange, substitution, or other event that results in a
change of the number and/or class of the securities issuable upon exercise or
conversion of this Warrant, Holder shall be entitled to receive, upon exercise
or conversion of this Warrant, the number and kind of securities and property
that Holder would have received for the Shares if this Warrant had been
exercised immediately before such reclassification, exchange, substitution, or
other event.  Such an event shall include any automatic conversion of the
outstanding or issuable securities of the Company of the same class or series as
the Shares to common stock pursuant to the terms of the Company's Articles of
Incorporation upon the closing of a registered public offering of the Company's
common stock.  The Company or its successor shall promptly issue to Holder a new
Warrant for such new securities or other property.  The new Warrant shall
provide for adjustments which shall be as nearly equivalent as may be
practicable to the adjustments provided for in this Article 2 including, without
limitation, adjustments to the Warrant Price and to the number of securities or
property issuable upon exercise of the new Warrant.  The provisions of this
Section 2.2 shall similarly apply to successive reclassifications, exchanges,
substitutions, or other events.

          2.3      ADJUSTMENTS FOR COMBINATIONS, ETC.  If the outstanding Shares
are combined or consolidated, by reclassification or otherwise, into a lesser
number of shares, the Warrant Price shall be proportionately increased.

          2.4      ADJUSTMENTS FOR ADDITIONAL ISSUANCES.  The number of Shares
issuable upon exercise of this Warrant shall be subject to adjustment, from time
to time, as set forth in this Section 2.4.  The term "Silicon Percentage
Interest" shall mean the ratio of the number of shares subject of this Warrant
as of the date hereof to the number of fully diluted shares of the Company as in
effect as of the date hereof.  At such time, and from time to time, that the
number of fully diluted shares of the Company increases, the number of shares
subject of this Warrant shall be considered increased by such an amount in order
to maintain in effect the Silicon Percentage Interest at all times with respect
to the number of shares subject of this Warrant as a ratio to the then increased
number of fully diluted shares, provided in no instance shall the number of
                                --------                                   
shares subject of this Warrant be reduced.

          As used herein the number of fully diluted shares means the aggregate
amount of all common stock (including reissued shares) issued (or deemed to be
issued as noted in the following sentences).  The shares of common stock
ultimately issuable upon exercise of an option (including the shares of common
stock ultimately issuable upon conversion or exercise of a convertible security
issuable pursuant to an option) are deemed to be issued when the option is
Issued.  The shares of common stock ultimately issuable upon conversion or
exercise of a convertible security (other than a convertible security issued
pursuant to an option) shall be deemed Issued upon issuance of the convertible
security.

          2.5      NO IMPAIRMENT.  The Company shall not, by amendment of its
Articles of Incorporation or through a reorganization, transfer of assets,
consolidation, merger, dissolution, issue, or sale of securities or any other
voluntary action, avoid or seek to avoid the observance or performance of any of
the terms to be observed or performed under this Warrant by the Company, but
shall at all times in good faith assist in carrying out of all the provisions of
this Article 2 and in taking all such action as may be necessary or appropriate
to protect Holder's rights under this Article against impairment.  If the
Company takes any action affecting the Shares or its common stock other than as
described above that adversely affects Holder's rights under this Warrant, the
Warrant Price shall be adjusted downward and the number of Shares issuable 

                                      -2-
<PAGE>
 
Silicon Valley Bank                                    Warrant to Purchase Stock
--------------------------------------------------------------------------------

upon exercise of this Warrant shall be adjusted upward in such a manner that the
aggregate Warrant Price of this Warrant is unchanged.

          2.6      FRACTIONAL SHARES.  No fractional Shares shall be issuable
upon exercise or conversion of the Warrant and the number of Shares to be issued
shall be rounded down to the nearest whole Share.  If a fractional share
interest arises upon any exercise or conversion of the Warrant, the Company
shall eliminate such fractional share interest by paying Holder amount computed
by multiplying the fractional interest by the fair market value of a full Share.

          2.7      CERTIFICATE AS TO ADJUSTMENTS.  Upon each adjustment of the
Warrant Price, the Company at its expense shall promptly compute such
adjustment, and furnish Holder with a certificate of its Chief Financial Officer
setting forth such adjustment and the facts upon which such adjustment is based.
The Company shall, upon written request, furnish Holder a certificate setting
forth the Warrant Price in effect upon the date thereof and the series of
adjustments leading to such Warrant Price.

ARTICLE 3.  REPRESENTATIONS AND COVENANTS OF THE COMPANY.

          3.1      REPRESENTATIONS AND WARRANTIES.  The Company hereby
represents and warrants to the Holder as follows:

          (a) The initial Warrant Price referenced on the first page of this
Warrant is not greater than (i) the price per share at which the Shares were
last issued in an arms-length transaction in which at least $500,000 of the
Shares were sold and (ii) the fair market value of the Shares as of the date of
this Warrant.

          (b) All Shares which may be issued upon the exercise of the purchase
right represented by this Warrant, and all securities, if any, issuable upon
conversion of the Shares, shall, upon issuance, be duly authorized, validly
issued, fully paid and non-assessable, and free of any liens and encumbrances
except for restrictions on transfer provided for herein or under applicable
federal and state securities laws.

          3.2      NOTICE OF CERTAIN EVENTS.  If the Company proposes at any
time (a) to declare any dividend or distribution upon its common stock, whether
in cash, property, stock, or other securities and whether or not a regular cash
dividend; (b) to offer for subscription pro rata to the holders of any class or
series of its stock any additional shares of stock of any class or series or
other rights; (c) to effect any reclassification or recapitalization of common
stock; (d) to merge or consolidate with or into any other corporation, or sell,
lease, license, or convey all or substantially all of its assets, or to
liquidate, dissolve or wind up; or (e) offer holders of registration rights the
opportunity to participate in an underwritten public offering of the company's
securities for cash, then, in connection with each such event, the Company shall
give Holder (1) at least 20 days prior written notice of the date on which a
record will be taken for such dividend, distribution, or subscription rights
(and specifying the date on which the holders of common stock will be entitled
thereto) or for determining rights to vote, if any, in respect of the matters
referred to in (c) and (d) above; (2) in the case of the matters referred to in
(c) and (d) above at least 20 days prior written notice of the date when the
same will take place (and specifying the date on which the holders of common
stock will be entitled to exchange their common stock for securities or other
property deliverable upon the occurrence of such event); and (3) in the case of
the matter referred to in (e) above, the same notice as is given to the holders
of such registration rights.

          3.3      INFORMATION RIGHTS.  So long as the Holder holds this Warrant
and/or any of the Shares, the Company shall deliver to the Holder (a) promptly
after mailing, copies of all notices or other written communications to the
shareholders of the Company, (b) within ninety (90) days after the end of each
fiscal year of the Company, the annual audited financial statements of the
Company certified by independent public accountants of recognized standing and
(c) within forty-five (45) days after the end of each of the first three
quarters of each fiscal year, the Company's quarterly, unaudited financial
statements.

          3.4      REGISTRATION UNDER SECURITIES ACT OF 1933, AS AMENDED.  The
Company agrees that the Shares or, if the Shares are convertible into common
stock of the Company, such common stock, shall be subject to the registration
rights set forth on Exhibit B, if attached.

ARTICLE 4.  MISCELLANEOUS.
            ------------- 

          4.1      TERM: NOTICE OF EXPIRATION.  This Warrant is exercisable, in
whole or in part, at any time and from time to time on or before the Expiration
Date set forth above.  The Company shall give Holder written notice of Holder's
right to exercise this Warrant in the form attached as Appendix 2 not more than
90 days and not less than 30 days before the Expiration Date. If the notice is
not so given, the Expiration Date shall automatically be extended until 30 days
after the date the Company delivers the notice to Holder.

          4.2      LEGENDS.  This Warrant and the Shares (and the securities
issuable, directly or indirectly, upon conversion of the Shares, if any) shall
be imprinted with a legend in substantially the following form:

          THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
1933, AS AMENDED, AND MAY NOT BE SOLD, PLEDGED OR OTHERWISE TRANSFERRED WITHOUT
AN EFFECTIVE REGISTRATION THEREOF UNDER SUCH ACT OR PURSUANT TO RULE 144 OR AN
OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE CORPORATION AND ITS COUNSEL
THAT SUCH REGISTRATION IS NOT REQUIRED.

          4.3      COMPLIANCE WITH SECURITIES LAWS ON TRANSFER.  This Warrant
and the Shares issuable upon exercise this Warrant (and the securities issuable,
directly or indirectly upon conversion of the Shares, if any) may not be
transferred or assigned in whole or in part without 

                                      -3-
<PAGE>
 
Silicon Valley Bank                                    Warrant to Purchase Stock
--------------------------------------------------------------------------------

compliance with applicable federal and state securities laws by the transferor
and the transferee (including, without limitation, the delivery of investment
representation letters and legal opinions reasonably satisfactory to the
Company, if reasonably requested by the Company). The Company shall not require
Holder to provide an opinion of counsel if the transfer is to an affiliate of
Holder or if there is no material question as to the availability of current
information as referenced in Rule 144(c), Holder represents that it has complied
with Rule 144(d) and (e) in reasonable detail, the selling broker represents
that it has complied with Rule 144(f), and the Company is provided with a copy
of Holders notice of proposed sale.

          4.4      TRANSFER PROCEDURE.  Subject to the provisions of Section 4.2
and Section 4.3, Holder may transfer all or part of this Warrant or the Shares
issuable upon exercise of this Warrant (or the securities issuable, directly or
indirectly, upon conversion of the Shares, if any) by giving the Company notice
of the portion of the Warrant being transferred setting forth the name, address
and taxpayer identification number of the transferee and surrendering this
Warrant to the Company for reissuance to the transferee(s) (and Holder if
applicable).  Unless the Company is filing financial information with the SEC
pursuant to the Securities Exchange Act of 1934, the Company shall have the
right to refuse to transfer any portion of this Warrant to any person who
directly competes with the Company.

          4.5      NOTICES.  All notices and other communications from the
Company to the Holder, or vice versa, shall be deemed delivered and effective
when given personally or mailed by first-class registered or certified mail,
postage prepaid, at such address as may have been furnished to the Company or
the Holder, as the case may be, in writing by the Company or such holder from
time to time.

          4.6      WAIVER.  This Warrant and any term hereof may be changed,
waived, discharged or terminated only by an instrument in writing signed by the
party against which enforcement of such change, waiver, discharge or termination
is sought.

          4.7      ATTORNEYS FEES.  In the event of any dispute between the
parties concerning the terms and provisions of this Warrant, the party
prevailing in such dispute shall be entitled to collect from the other party all
costs incurred in such dispute, including reasonable attorneys' fees.

          4.8      GOVERNING LAW.  This Warrant shall be governed by and
construed in accordance with the laws of the State of California, without giving
effect to its principles regarding conflicts of law.

                                       NETVANTAGE, INC.


                                       By /s/ Stephen R. Rizzone
                                         -----------------------------------
                                         Chairman of the Board, President or
                                         Vice President


                                       By /s/ Thomas V. Baker
                                         -----------------------------------
                                         Secretary or Ass't Secretary

                                      -4-