<PAGE>   1
                                                                  EXHIBIT 10.30c

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                    INTELLECTUAL PROPERTY SECURITY AGREEMENT




                                    Between

                                  XIRCOM, INC.
                                   as Debtor

                                      and

                           NATIONSBANK OF TEXAS, N.A.
                              Administrative Agent





                               December 30, 1996


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<PAGE>   2
                               TABLE OF CONTENTS
<TABLE>
<CAPTION>
                                                                                                Page
                                                                                                ----
<S>     <C>                                                                                       <C>
                                                I.  GRANT OF SECURITY INTEREST
                                                    --------------------------
1.01.   Grant of Security Interest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     1
1.02.   Security for Obligations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     1
1.03.   Validity and Priority of Security Interest . . . . . . . . . . . . . . . . . . . . . .     2
1.04.   Maintenance of Status of Security Interest, Collateral and Rights  . . . . . . . . . .     2
        (a)      Required Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     2
        (b)      Protection of Collateral  . . . . . . . . . . . . . . . . . . . . . . . . . .     2
        (c)      Authorized Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     3
        (d)      Registrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     3
1.05.   Debtor Remains Obligated; Administrative Agent and Secured Parties Not Obligated . . .     3
1.06.   Termination  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     3
1.07.   Security Interest Absolute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     4
2.01.   Authorization; Enforceability; Required Consents; Absence of Conflicts . . . . . . . .     4
2.02.   Rights of Debtor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     4
2.03.   Perfection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     5
2.06.   Registrations  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     5
2.07.   Other Property . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     5

                                                        III.  COVENANTS
                                                              ---------

3.01.   Chief Executive Office . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     5
3.02.   Preservation of Existence and Preservation of Enforceability . . . . . . . . . . . . .     5
3.03.   Requested Information  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     5
3.04.   No Disposition of Collateral . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     6
3.05.   Additional Property  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     6

                                                     IV. EVENT OF DEFAULT
                                                         ----------------

4.01.   Application of Proceeds  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     6
4.02.   Remedies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     6
4.03.   Indemnity and Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     7

                                                      V.  INTERPRETATION
                                                          --------------

5.01.   Definitional Provision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     8
        (a)      Certain Terms Defined by Reference  . . . . . . . . . . . . . . . . . . . . .     8
        (b)      Other Defined Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     8
        (c)      Other Definitional Provisions . . . . . . . . . . . . . . . . . . . . . . . .    10
5.02.   Power of Attorney  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    10

                                                      VI.  MISCELLANEOUS
                                                           -------------

6.01.   Expenses of Debtor's Agreements and Duties . . . . . . . . . . . . . . . . . . . . . .    10
6.02.   Administrative Agent's Right to Perform on Debtor's Behalf . . . . . . . . . . . . . .    11
6.03.   Administrative Agent's Right to Use Agents . . . . . . . . . . . . . . . . . . . . . .    11
6.04.   No Interference, Compensation or Expense . . . . . . . . . . . . . . . . . . . . . . .    11
</TABLE>
<PAGE>   3
<TABLE>
<S>     <C>                                                                                           <C>
6.05.   Limitation of Administrative Agent's Obligations With Respect to Collateral  . . . . . . .    11
6.06.   Rights of Administrative Agent under UCC and Applicable Law  . . . . . . . . . . . . . . .    11
6.07.   Waivers of Rights Inhibiting Enforcement . . . . . . . . . . . . . . . . . . . . . . . . .    12
6.08.   Notices and Deliveries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    12
6.09.   Rights and Remedies Cumulative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    12
6.10.   Amendments; Waivers  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    12
6.11.   GOVERNING LAW  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    12
6.12.   WAIVER OF JURY TRIAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    13
6.13.   Consent to Jurisdiction; Waiver of Immunities  . . . . . . . . . . . . . . . . . . . . . .    13
6.14.   Severability of Provisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    13
6.15.   Counterparts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    13
6.16.   Successors and Assigns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    14
6.17.   Loan Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    14
6.18.   Obligations Not Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    14
6.19.   ENTIRE AGREEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    14
</TABLE>



                                     - ii -
<PAGE>   4
                    INTELLECTUAL PROPERTY SECURITY AGREEMENT


         INTELLECTUAL PROPERTY SECURITY AGREEMENT, dated as of December 30,
1996, between Xircom, Inc., a California corporation ("Debtor"), and
NationsBank of Texas, N.A., a national banking association, as Administrative
Agent ("Administrative Agent"), for itself and each other lender a party to the
Credit Agreement described below (singly, a "Secured Party" and collectively,
the "Secured Parties").


                                   RECITALS.

         (1)     Administrative Agent, Debtor, and Secured Parties entered into
the Credit Agreement dated as of December 30, 1996 (as the same has been and
may hereafter be supplemented, amended, amended and restated, extended or
modified from time to time, being the "Credit Agreement").

         (2)     It is the intention of the parties hereto that this Agreement
create a first priority security interest securing the payment of the
obligations set forth in Section 1.02 hereof.

         (3)     It is a condition precedent to the effectiveness of the Credit
Agreement that Debtor shall have executed and delivered this Agreement.


                                   AGREEMENT.

         NOW, THEREFORE, in consideration of the premises set forth herein and
for other good and valuable consideration, the receipt and sufficiency of which
is hereby acknowledged, and in order to induce Secured Parties to, among other
things, make Advances under the Credit Agreement, Debtor hereby agrees with
Administrative Agent for its benefit and the ratable benefit of Secured Parties
as hereinafter set forth.


                         I.  GRANT OF SECURITY INTEREST

         1.01.   Grant of Security Interest.  Debtor hereby pledges and grants
to Administrative Agent for its benefit and the ratable benefit of Secured
Parties a security interest in, the entire right, title and interest of Debtor,
in and to the Collateral.

         1.02.   Security for Obligations. This Agreement creates a first
priority security interest, securing the payment and performance of any and all
obligations now or hereafter existing of Debtor, each Obligor and any other
Person under the Credit Agreement and the other Loan Documents, including any
extensions, modifications, substitutions, amendments and renewals thereof,
whether for principal, interest, fees, expenses, indemnification or otherwise)
(all such obligations of Debtor, each Obligor and each other Person being the
"Obligations").  Without limiting the generality of the foregoing, this
Agreement secures the payment of all amounts which constitute part of the
Obligations and would be owed by Debtor, each other Obligor and any other
Person to Administrative Agent or any Secured Party under any Loan Document,
but for the fact that they are unenforceable or not allowable due to the
existence of a bankruptcy, reorganization or similar proceeding under any
Debtor Relief Law involving Debtor, any other Obligor or any other
<PAGE>   5
Person (including all such amounts which would become due or would be secured
but for the filing of any petition in bankruptcy, or the commencement of any
insolvency, reorganization or like proceeding of Debtor, any other Obligor or
any other Person under any Debtor Relief Law).

         1.03.   Validity and Priority of Security Interest.  Debtor agrees
that the Security Interest shall at all times be valid, perfected, continuing
and binding and enforceable against Debtor and all other Persons, in accordance
with the terms hereof, as security for the Obligations, and that the Collateral
shall not at any time be subject to any Lien, except as permitted in the Loan
Documents.

         1.04.   Maintenance of Status of Security Interest, Collateral and
Rights.

         (a)     Required Action.  Debtor shall take all reasonable action that
may be necessary or that Administrative Agent may reasonably request, so as at
all times (i) to maintain the validity, perfection, enforceability and priority
of the Security Interest in the Collateral in conformity with the requirements
of Section 1.03, and (ii) to protect and preserve, and to enable the exercise
or enforcement of, the rights of Administrative Agent hereunder, including (A)
immediately discharging all Liens, except as permitted in the Loan Documents
and by any license entered into in the ordinary course of business and (B)
executing and delivering financing or continuation statements, instruments of
pledge, notices and instructions in each case in form and substance reasonably
satisfactory to Administrative Agent.

         (b)     Protection of Collateral.  Debtor shall use its best efforts
to protect, preserve, renew and maintain, in each case in a manner consistent
with reasonably responsible business and legal practices all rights of Debtor
in the Collateral (except to the extent such Collateral is obsolete or no
longer useful to Debtor's business), including (i) prosecuting such suits,
proceedings or other actions for infringement, unfair competition, dilution or
other damage or (ii) appearing in and defending any action or proceeding that
may materially adversely affect Debtor's title to or Administrative Agent's
security interest in all or any material part of the Collateral, when such
action is in Debtor's reasonable business judgment necessary to protect
Debtor's Collateral.  Any reasonable expenses incurred in protecting,
preserving, renewing and maintaining the Collateral shall be borne by Debtor.
To the maximum extent permitted by Laws, after a Default or Event of Default
shall have occurred and be continuing, Administrative Agent shall have the
right, without taking title to any Collateral, to bring suit to enforce any or
all Collateral or its Security Interest in any or all of the Collateral, in
which event Debtor shall, at the reasonable request of Administrative Agent, do
any and all lawful acts and execute any and all proper documents reasonably
required by Administrative Agent in aid of such enforcement.  All reasonable
costs, reasonable expenses and other moneys reasonably advanced by
Administrative Agent in connection with the foregoing shall, whether or not
there are then outstanding any amounts under the Credit Agreement, be treated
as Obligations, but the making of any Advances by Administrative Agent or any
Secured Party shall not relieve Debtor of any default hereunder.

         (c)     Authorized Action.  Administrative Agent is hereby authorized
to file one or more financing or continuation statements, amendments thereto
and instruments of pledge, notices and instructions without the signature of or
in the name of Debtor when permitted by Applicable Law provided that
Administrative Agent shall give reasonably prompt notice of any such filings to
Debtor.  A carbon, photographic or other reproduction of this Agreement or of
any financing statement filed in connection with this Agreement shall be
sufficient as a financing statement.

         (d)     Registrations.  Debtor shall renew or maintain, as specified
in any Applicable Law,





                                     - 2 -
<PAGE>   6
and shall make any filings necessary to renew or maintain the Registrations,
except to the extent such Collateral is obsolete or no longer useful to
Debtor's business.

         1.05.   Debtor Remains Obligated; Administrative Agent and Secured
Parties Not Obligated.  The grant by Debtor to Administrative Agent of the
Security Interest shall not relieve Debtor from the performance of any term,
covenant, condition or agreement on its part to be performed or observed
(including by virtue of the exercise by Administrative Agent of any of its
rights hereunder), or from any liability to any Person, under or in respect of
any of the Collateral or impose any obligation on Administrative Agent or any
Secured Party or impose any liability on Administrative Agent or any Secured
Party for any act or omission on the part of Debtor relative thereto.

         1.06.   Termination.

         (a)     In the event that the Obligations shall have been finally paid
in full, and all commitments by Secured Parties to extend credit shall have
been terminated and Administrative Agent shall have delivered to Debtor a
written termination agreement, then this Agreement shall also terminate and be
of no further force and effect (except as provided in Section 1.06(b)).

         (b)     Debtor agrees that, if at any time all or any part of any
payment theretofore applied by Administrative Agent and Secured Parties to any
of the Obligations is or must be rescinded or returned by any Person for any
reason whatsoever (including the insolvency, bankruptcy or reorganization of
Debtor or any other Person), such Obligations shall, for the purposes of this
Agreement, to the extent that such payment is or must be rescinded or returned,
be deemed to have continued in existence, notwithstanding such application by
Administrative Agent or any Secured Party, and the Security Interest granted
hereunder shall continue to be effective or be reinstated, as the case may be,
as to such Obligations, all as though such application by Administrative Agent
or any Secured Party had not been made.

         1.07.   Security Interest Absolute.  All rights of Administrative
Agent and Secured Parties and the Security Interest granted to Administrative
Agent hereunder, and all obligations of Debtor hereunder, shall, to the extent
permitted by Laws, be absolute and unconditional, irrespective of

         (a)     any lack of validity or enforceability of any Loan Documents;

         (b)     any change in the time, manner or place of payment or
performance of, or in any other term of, all or any of the Obligations or any
other amendment to or waiver of or any consent to departure from any Loan
Documents;

         (c)     any exchange, release or non-perfection of any collateral
(including the Collateral or any part thereof), or any release of or amendment
to or waiver of or consent to departure from any guaranty, for all or any of
the Obligations; or

         (d)     any other circumstances which might otherwise constitute a
defense available to, or a discharge of, Debtor, any other Obligor or any other
Person.


                      II.  REPRESENTATIONS AND WARRANTIES





                                     - 3 -
<PAGE>   7
         Debtor represents and warrants as follows:

         2.01.   Authorization; Enforceability; Required Consents; Absence of
Conflicts.  Debtor has the power, and has taken all necessary action to
authorize it, to execute, deliver and perform in accordance with its terms this
Agreement and to execute and deliver all financing statements and other filings
contemplated hereby.  This Agreement has been duly executed and delivered by
Debtor and is the legal, valid and binding obligation of Debtor, enforceable in
accordance with its terms subject to (i) equitable principles generally and
(ii) Debtor Relief Laws.  The execution, delivery and performance in accordance
with its terms by Debtor of this Agreement does not and (absent any change in
any Law) will not (a) except for the filing and acceptance of financing
statements and continuation statements in connection therewith delivered to
Administrative Agent describing this Agreement and the Collateral under the
Code and the filing of this Agreement with the United States Patent and
Trademark Office and acceptance thereof to the extent permitted by Applicable
Law, require any Governmental Approval or any other consent or approval,
including any consent or approval of any shareholder of Debtor, (b) violate or
conflict with its articles or bylaws, or (c) violate or conflict with, result
in a breach of, constitute a default under, or result in or require the
creation of any Lien (other than the Security Interest) upon any assets of
Debtor under any contract or agreement or Applicable Laws.

         2.02.   Rights of Debtor.  Debtor is the legal and beneficial owner of
the Collateral free and clear of any Lien or other charge or encumbrance,
including, without limitation, pledges, assignments, licenses, shop rights and
covenants by Debtor not to sue any Person, except for the security interests
and assignment created by this Agreement any other Liens permitted under the
Credit Agreement.  No effective financing statement or other instrument similar
in effect naming Debtor as "debtor" covering all or any part of the Collateral
is on file in any recording office, except such as may have been filed in favor
of Administrative Agent relating to this Agreement.

         2.03.   Perfection.  This Agreement, together with the filings
referred to in Section 2.01(a) above, will create in favor of Administrative
Agent valid and perfected security interests in the Collateral and such
security interests will be a first priority security interest; provided that
additional actions may be required with respect to the perfection of proceeds
of the Collateral held on the date hereof.

         2.06.   Registrations.  Annexes A-1, A-2, B-1, B-2, C-1 and C-2, as
applicable, set forth a true and complete list of all Registrations in the
United States Patent and Trademark Office and related state filings owned by
Debtor as of the date hereof.

         2.07.   Other Property.  On the date hereof, Debtor has no interest in
any Copyrights, which are registered or subject to any application for
registration and Debtor does not believe, after appropriate review of all
relevant facts and circumstances, that any registration or filing with respect
to any interest Debtor may have in any property which may constitute Copyrights
is material to the operation of Debtor's existing and anticipated business.


                                III.  COVENANTS

         3.01.   Chief Executive Office.  Debtor shall maintain its chief
executive office and the office where the books and records relating to the
Collateral are kept only at 2300 Corporate Center Drive, Thousand Oaks,
California 91320.





                                     - 4 -
<PAGE>   8
         3.02.   Preservation of Existence and Preservation of Enforceability.
Debtor shall, so long as any of the Obligations remain outstanding, (a)
preserve and maintain its existence and (b) take all reasonable action and
obtain all consents and Government Approvals reasonably required so that its
obligations under this Agreement will at all times be legal, valid and binding
and enforceable in accordance with its terms.

         3.03.   Requested Information.  In addition to such other Information
as shall be specifically provided for herein, Debtor shall furnish to
Administrative Agent such other Information with respect to the Collateral as
Administrative Agent may reasonably request from time to time in connection
with the Collateral, or the protection, preservation, maintenance or
enforcement of the Security Interest or the Collateral.  In connection with its
enforcement of the Security Interest, Administrative Agent may use such
Information or transfer it to any assignee or sublicensee permitted hereunder
for such assignee's or sublicensee's use.

         3.04.   No Disposition of Collateral.  Debtor shall not sell, transfer
or otherwise dispose of any of the Collateral or any interest therein that is
material to Debtor's business, or grant any license thereunder, except in the
ordinary course of business and except to the extent the same is obsolete or no
longer useful to Debtor's business.

         3.05.   Additional Property.  Prior to the application for, use or
acquisition or any interest in any property which is within the definition of
"Collateral" or modification, reformulation or other alteration to any such
interest that is material to Debtor's business, Debtor shall execute and
deliver to Administrative Agent all documents and instruments Administrative
Agent may require to grant to Administrative Agent a perfected first priority
Lien therein and to subject to all of such interest to this Agreement,
including but not limited to any new, supplementary or additional filings in
the form of Schedule 1.04(a)(ii)(B)-A, -B, or -C.


                              IV. EVENT OF DEFAULT

         Upon the occurrence and during the continuance of an Event of Default:

         4.01.   Application of Proceeds.  All cash proceeds received by
Administrative Agent upon any sale of, collection of, or other realization
upon, all or any part of the Collateral shall be applied as follows:

         First:  To the payment of all reasonable out-of-pocket costs and
expenses incurred in connection with the sale of, collection of or other
realization upon Collateral, including reasonable attorneys' fees and
disbursements;

         Second:  To the payment of the Obligations as provided in the Credit
Agreement (with Debtor remaining liable for any deficiency); and

         Third:  To the extent of the balance (if any) of such proceeds, to the
payment to Debtor or other Person entitled thereto.

         4.02.   Remedies.





                                     - 5 -
<PAGE>   9
         (a)     If an Event of Default has occurred and is continuing and the
Obligations have been accelerated, Administrative Agent may exercise in respect
of the Collateral, in addition to other rights and remedies provided for herein
or otherwise available to it, all the rights and remedies of a secured party on
default under the Uniform Commercial Code in effect in the State of Texas at
that time (the "UCC") (whether or not the Uniform Commercial Code applies to
the affected Collateral), and also may (i) require Debtor to, and Debtor hereby
agrees that it will at its expense and upon request of Administrative Agent
forthwith, assemble all or part of the Collateral (to the extent capable of
being assembled) as directed by Administrative Agent and make it available to
Administrative Agent at a place to be designated by Administrative Agent, which
is reasonably convenient to both parties or (ii) without notice, except as
specified below, sell the Collateral or any portion thereof in one or more
parcels at public or private sale, at any of Administrative Agent's offices or
elsewhere, for cash, on credit or for future delivery, and upon such other
terms as Administrative Agent may deem commercially reasonable.  Debtor agrees
that, to the extent notice of sale shall be required by Applicable Law, ten
days' written notice to Debtor of the time and place of any public sale or the
time after which any private sale is to be made shall constitute reasonable
notification, provided that ten days' written notice does not violate any
Applicable Law.  Administrative Agent shall not be obligated to make any sale
of Collateral regardless of notice of sale having been given.  Administrative
Agent may adjourn any public or private sale from time to time by announcement
at the time and place fixed therefor, and such sale may, without further
notice, be made at the time and place to which it was so adjourned.

         (b)     Upon written demand of Administrative Agent, Debtor shall
execute and deliver to Administrative Agent an assignment or assignments of the
Collateral and such other documents as are necessary and appropriate to carry
out the intent and purposes of this Agreement.  Debtor agrees that such an
assignment and/or recording shall be applied to reduce the Obligations
outstanding only to the extent that Administrative Agent or any Lenders
receives cash proceeds in respect of the sale of, or realization upon, the
Collateral.

         4.03.   Indemnity and Expenses.

         (A)     DEBTOR AGREES TO INDEMNIFY (WHICH SHALL BE PAYABLE FROM TIME
TO TIME ON DEMAND) ADMINISTRATIVE AGENT AND SECURED PARTIES FROM AND AGAINST
ANY AND ALL CLAIMS, LOSSES AND LIABILITIES GROWING OUT OF OR RESULTING FROM
THIS AGREEMENT (INCLUDING ENFORCEMENT OF THIS AGREEMENT), EXPRESSLY INCLUDING
SUCH CLAIMS, LOSSES, OR LIABILITIES ARISING OUT OF MERE NEGLIGENCE OF
ADMINISTRATIVE AGENT OR ANY SECURED PARTY, EXCEPT CLAIMS, LOSSES OR LIABILITIES
RESULTING SOLELY FROM ADMINISTRATIVE AGENT'S OR ANY SECURED PARTY'S GROSS
NEGLIGENCE OR WILLFUL MISCONDUCT.

         (b)     Debtor will upon demand pay to Administrative Agent and
Secured Parties the amount of any and all reasonable expenses, including the
reasonable fees and disbursements of its counsel and of any experts and agents,
which Administrative Agent and Secured Parties may incur in connection with (i)
the custody, preservation, use or operation of, or the sale of, collection
from, or other realization upon, any of the Collateral, (ii) the exercise or
enforcement of any of the rights of Administrative Agent and Secured Parties
hereunder, or (iii) the failure by Debtor to perform or observe any of the
provisions hereof.  Debtor will pay upon demand to Administrative Agent the
amount of any and all reasonable fees and disbursements of its counsel and of
any experts and agents, which Administrative Agent may incur in connection with
the administration of this





                                     - 6 -
<PAGE>   10
Agreement.


                               V.  INTERPRETATION

         5.01.   Definitional Provision.

         (a)     Certain Terms Defined by Reference.  The terms "collateral",
"inventory", "rights", and "security interest" shall have the meanings ascribed
thereto in the UCC, or, when capitalized, the meanings specified in subsection
(b) below.

         (b)     Other Defined Terms.  For purposes of this Agreement:

         "Agreement" means this Agreement, including all schedules, annexes and
exhibits hereto.

         "Collateral" means Debtor's rights, title and interests, (whatever
they may be) in each of the following, in each case whether now or hereafter
existing or now owned or hereafter acquired by Debtor and whether or not the
same is subject to Article 9 of the UCC, and wherever the same may be located:

         (i)     the Trademarks and Goodwill;

         (ii)    the Copyrights;

         (iii)   the Patents;

         (iv)    all registrations issued or applied for (now or hereafter) on
the Trademarks, Copyrights and Patents and renewals thereof in the United
States and any state thereof (the "Registrations");

         (v)     any renewal, reissue, re-examination certificate, extension or
the like with respect to the Trademarks, Patents, Copyrights;

         (vi)    all rights to use the Trademarks as trade names or assumed
names in all aspects of its business; and

         (vii)   all proceeds and products of the foregoing together with any
license in favor of or from Debtor of any of the foregoing in whatever form.
The inclusion of "proceeds" of Collateral in the definition of "Collateral"
shall not be deemed a consent by Administrative Agent to any sale or other
disposition of any Collateral not otherwise specifically permitted by the terms
hereof.

         "Copyright" means any copyright, copyright registration and
applications for such registration, including but not limited to the copyrights
listed on Annex C-1 attached hereto, all subject matter related to such
copyrights, in any and all forms, and all copyrights and applications for
copyrights related to such copyrights, including those copyrights and
applications listed in Annex C-2 attached hereto.

         "Credit Agreement" is defined in the recitals.





                                     - 7 -
<PAGE>   11
         "Event of Default" means those events described as a "Default" or an
"Event of Default" in the  Credit Agreement.

         "Goodwill" means the goodwill of the businesses connected with the use
of (or associated with) and symbolized by the Trademarks, but not any other
goodwill.

         "Governmental Approval" means any authorization, consent, approval,
license or exemption of, registration or filing with, or report or notice to,
any Tribunal.

         "Information" means data, certificates, reports, statements (including
financial statements), documents and other information in form (including
electronic media) acceptable to Administrative Agent.

         "Lien" means, with respect to any property or asset of any Person (in
each case whether the same is consensual or nonconsensual or arises by
contract, operation of law, legal process or otherwise) (i) any mortgage, lien,
pledge, attachment, levy, priority or other security interest or encumbrance of
any kind thereupon or in respect thereof and (ii) any arrangement, express or
implied, under which the same is subordinated, transferred, sequestered or
otherwise identified so as to subject the same, or make the same available for,
the payment or performance of any obligation in priority to the payment of the
ordinary, unsecured creditors of such Person.

         "Loan Documents" means the Credit Agreement and each agreement,
certificate and other documents delivered to any Person pursuant to the Credit
Agreement.

         "Obligations" is defined in Section 1.02.

         "Patents" means all patents, all inventions and subject matter related
to such patents, in any and all forms, and all patents and applications for
patents related to such patents, including but not limited to the patents
listed on Annex A-1 attached hereto, all inventions and all subject matter
related to such patents, in any and all forms, and all patents and applications
for patents related to such patents, including those patents and applications
listed on Annex A-2 attached hereto.

         "Person" means an individual, firm, corporation, partnership,
association, joint venture, trust or any other entity or organization or
Tribunal.

         "Security Interest" means the continuing security interest of
Administrative Agent and assignment to Administrative Agent in the Collateral
intended to be effected by the terms of this Agreement or any financing and
continuation statements or other filings contemplated hereby.

         "Trademarks" means all trademarks, all designs and logotypes related
to such trademarks, in any and all forms, and all trademark registrations and
applications for registration related to such trademarks, including but not
limited to the trademarks listed on Annex B-1 attached hereto, all designs and
logotypes related to such trademarks, in any and all forms, and all trademark
registrations and applications for registration related to such trademarks,
including those registrations and applications listed on Annex B-2 attached
hereto.

         "UCC" means Article 9 of the Uniform Commercial Code as in effect from
time to time in the State of Texas.





                                     - 8 -
<PAGE>   12
         (c)     Other Definitional Provisions.  (i) Except as otherwise
specified herein, all references herein (A) to any Person shall be deemed to
include such Person's successors and assigns, (B) to any Applicable Law
referred to herein shall be deemed references to such Applicable Law as the
same may have been or may be amended or supplemented from time to time and (C)
to this Agreement or other agreement defined or referred to herein shall be
deemed a reference to this Agreement or other agreement as the terms thereof
may have been or may be amended, supplemented, waived or otherwise modified
from time to time.

         (ii)    Whenever the context so requires, the neuter gender includes
the masculine or feminine, the masculine gender includes the feminine, and the
singular number includes the plural, and vice versa.

         (iii)   Except as otherwise indicated, any reference herein to the
"Collateral", the "Obligations" or any other collective or plural term shall be
deemed to be a reference to each and every item included within the category
described by such collective or plural term, so that a reference to the
"Collateral" or the "Obligations" shall be deemed a reference to any or all of
the Collateral or the Obligations, as the case may be.

         (iv)    Capitalized Terms not otherwise defined herein have the
meaning specified in the Credit Agreement, and, to the extent of any conflict,
terms as defined in the Credit Agreement shall control (provided, that a more
expansive or explanatory definition shall not be deemed a conflict).

         5.02.   Power of Attorney.  Each power of attorney, license and other
authorization in favor of Administrative Agent or any other Person granted by
or pursuant to this Agreement shall be deemed to be irrevocable and coupled
with an interest.


                               VI.  MISCELLANEOUS

         6.01.   Expenses of Debtor's Agreements and Duties.  Administrative
Agent and Secured Parties shall not be liable for the costs and expenses of
Debtor arising out of Debtor's performance or observance of the terms,
conditions, covenants and agreements to be observed or performed by Debtor
under this Agreement.

         6.02.   Administrative Agent's Right to Perform on Debtor's Behalf.
If Debtor shall fail to observe or perform any of the terms, conditions,
covenants and agreements to be observed or performed by it under this
Agreement, Secured Party may (but shall not be obligated to) do the same or
cause it to be done or performed or observed, either in its name or in the name
and on behalf of Debtor, and in the event that Debtor shall have failed to
observe or perform any of the terms, conditions, covenants and agreements to be
observed or performed by it under this Agreement, then Debtor hereby authorizes
Secured Party to do so, and Debtor hereby appoints the Secured Party, and any
other Person Secured Party may designate, as Debtor's attorney-in-fact
(exercisable from and after the occurrence of an Event of Default which is
continuing) to do, or cause to be done, in the name, place and stead of Debtor
in any way in which Debtor itself could do, or cause to be done, any or all
things necessary to observe or perform the terms, conditions, covenants and
agreements to be observed or performed by Debtor under this Agreement.  In
addition, Debtor hereby irrevocably appoints Secured Party as Debtor's
attorney-in-fact (exercisable from and after the occurrence and during the
continuance of an Event of Default which is continuing) to execute and deliver
in Debtor's name and stead to any purchaser at any sale held





                                     - 9 -
<PAGE>   13
under Section 4.02(b) hereof any and all documents and instruments of
assignment, transfer and conveyance necessary or appropriate to transfer to
such purchaser the Collateral sold at such sale.  Secured Party shall not
exercise any powers granted pursuant to this appointment as attorney-in-fact at
any time that Debtor is fully performing its obligations hereunder.  This
appointment as attorney-in-fact shall terminate upon the termination of this
Agreement.

         6.03.   Administrative Agent's Right to Use Agents.  Administrative
Agent may exercise its rights under this Agreement through an agent or other
designee.

         6.04.   No Interference, Compensation or Expense.  Administrative
Agent may exercise its rights under this Agreement (a) without resistance or
interference by Debtor and (b) without payment of any rent, license fee or
compensation of any kind to Debtor.

         6.05.   Limitation of Administrative Agent's Obligations With Respect
to Collateral.  (a) Administrative Agent shall not have any duty or liability
to protect or preserve any Collateral or to preserve rights pertaining thereto,
except to the extent of any gross negligence or willful misconduct of the
Administrative Agent.

         (b)     Nothing contained in this Agreement shall be construed as
requiring or obligating Administrative Agent, and Administrative Agent shall
not be required or obligated, to (i) present or file any claim or notice or
take any action, with respect to any Collateral or in connection therewith or
(ii) notify Debtor of any decline in the value of any Collateral.

         6.06.   Rights of Administrative Agent under UCC and Applicable Law.
Administrative Agent shall have, with respect to the Collateral, in addition to
all of their rights under this Agreement, (a) the rights of a secured party
under the UCC, whether or not the UCC would otherwise apply to the collateral
in question, and (b) the rights of a secured party under all other Applicable
Laws.

         6.07.   Waivers of Rights Inhibiting Enforcement.  Debtor waives (a)
to the extent not prohibited by Applicable Law, any claim that, as to any part
of the Collateral, a public sale, should Administrative Agent elect so to
proceed, is, in and of itself, not a commercially reasonable method of sale for
such Collateral, (b) except as otherwise provided in this Agreement, TO THE
EXTENT PERMITTED BY APPLICABLE LAW, NOTICE OR JUDICIAL HEARING IN CONNECTION
WITH ADMINISTRATIVE AGENT'S DISPOSITION OF ANY OF THE COLLATERAL INCLUDING ANY
AND ALL PRIOR NOTICE AND HEARING FOR ANY PREJUDGMENT REMEDY OR REMEDIES AND ANY
SUCH RIGHT THAT DEBTOR WOULD OTHERWISE HAVE UNDER THE CONSTITUTION OR ANY
STATUTE OF THE UNITED STATES OR OF ANY STATE, AND ALL OTHER REQUIREMENTS AS TO
THE TIME, PLACE AND TERMS OF SALE OR OTHER REQUIREMENTS WITH RESPECT TO THE
ENFORCEMENT OF ADMINISTRATIVE AGENT'S RIGHTS HEREUNDER and (c) all rights of
redemption, appraisement, or marshalling of assets.





                                     - 10 -
<PAGE>   14
         6.08.   Notices and Deliveries.  All notices and other communications
provided for hereunder shall be in writing and mailed, telecopied or delivered
by reputable overnight delivery service or by hand, if to the Debtor, addressed
to it at its address specified on the signature pages hereof, if to the
Administrative Agent, addressed to it at its address specified in the Credit
Agreement, or, as to each party, at such other address as shall be designated
by such party in a written notice to each other party complying as to delivery
with the terms of this Section 6.08.  All such notices and other communications
shall, when mailed, telecopied, or delivered, be effective three days after
being deposited in the mails, when telecopied with confirmation of receipt, or
when delivered by reputable overnight delivery service or by hand to the
addressee or its agent, respectively.

         6.09.   Rights and Remedies Cumulative.  Each of Administrative
Agent's rights and remedies under this Agreement shall be in addition to all of
its other rights and remedies under this Agreement and Applicable Law, and
nothing herein shall be construed as limiting any such rights or remedies.

         6.10.   Amendments; Waivers.  Any term, covenant, agreement or
condition of this Agreement may be amended, and any right under this Agreement
may be waived, if, but only if, such amendment or waiver is in writing and is
signed by Administrative Agent and, in the case of an amendment, by Debtor.
Unless otherwise specified in such waiver, a waiver of any right under this
Agreement shall be effective only in the specific instance and for the specific
purpose for which given.  No election not to exercise, failure to exercise or
delay in exercising any right, nor any course of dealing or performance, shall
operate as a waiver of any right of the Administrative Agent under this
Agreement or Applicable Law, nor shall any single or partial exercise of any
such right preclude any other or further exercise thereof or the exercise of
any other right of Administrative Agent under this Agreement or Applicable Law.

         6.11.   GOVERNING LAW.  THIS AGREEMENT SHALL BE GOVERNED BY AND
CONSTRUED IN ACCORDANCE WITH THE INTERNAL LAWS OF THE STATE OF TEXAS (WITHOUT
REFERENCE TO PRINCIPALS OF CONFLICTS OF LAWS) AND THE UNITED STATES OF AMERICA,
EXCEPT TO THE EXTENT THAT THE VALIDITY OR PERFECTION OF THE SECURITY INTEREST
HEREUNDER, OR REMEDIES HEREUNDER, IN RESPECT OF ANY PARTICULAR COLLATERAL ARE
REQUIRED TO BE GOVERNED BY THE LAWS OF A JURISDICTION OTHER THAN THE STATE OF
TEXAS.

         6.12.   WAIVER OF JURY TRIAL.  ADMINISTRATIVE AGENT AND DEBTOR HEREBY
WAIVE TRIAL BY JURY IN ANY JUDICIAL PROCEEDINGS INVOLVING, DIRECTLY OR
INDIRECTLY, ANY MATTER (WHETHER IN TORT, CONTRACT OR OTHERWISE) IN ANY WAY
ARISING OUT OF, RELATED TO, OR CONNECTED WITH THIS AGREEMENT OR THE
RELATIONSHIP ESTABLISHED HEREUNDER.

         6.13.   Consent to Jurisdiction; Waiver of Immunities.

         (a)     Debtor hereby irrevocably submits to the non-exclusive
jurisdiction of any United States Federal or Texas State courts sitting in
Dallas, Texas in any action or proceeding arising out of or relating to this
Agreement, and Debtor hereby irrevocably waives any objection it may now or
hereafter have as to the venue of any such suit, action or proceeding brought
in such court or that such court is an inconvenient forum.





                                     - 11 -
<PAGE>   15
         (b)     Nothing in this section shall limit the right of
Administrative Agent or any Secured Party to bring any action or proceeding
against Debtor or its property in the courts of any other jurisdictions.

         (c)     Any judicial proceeding by Debtor against Administrative Agent
or any Secured Party involving, directly or indirectly, any matter in any way
arising out of, related to, or connected with this Agreement shall be brought
only in a court in Dallas, Texas to the extent that jurisdiction may be
effected against such Person in Dallas, Texas.

         6.14.   Severability of Provisions.  Any provision of this Agreement
that is prohibited or unenforceable in any jurisdiction shall, as to such
jurisdiction, be ineffective to the extent of such prohibition or
unenforceability without invalidating the remaining provisions hereof in that
jurisdiction or affecting the validity or enforceability of such provision in
any other jurisdiction.  In the event that any change in Applicable Law would
render invalid or unenforceable any provision of this Agreement, Debtor agrees
to enter into such amendments or modifications to this Agreement to provide
Administrative Agent with benefits intended to be granted by such provision.

         6.15.   Counterparts.  This Agreement may be signed in any number of
counterparts, each of which shall be an original, with the same effect as if
the signatures thereto were upon the same instrument.

         6.16.   Successors and Assigns.  All of the provisions of this
Agreement shall be binding and inure to the benefit of the parties hereto and
their respective successors and permitted assigns; provided, Debtor may not
assign its rights or obligations under this Agreement without the prior written
consent of the Lenders.

         6.17.   Loan Documents.  This Agreement is a Loan Document executed
pursuant to the Credit Agreement and shall (unless otherwise expressly
indicated herein) be construed, administered and applied in accordance with the
terms and provisions thereof.

         6.18.   Obligations Not Affected.  To the fullest extent permitted by
Applicable Law, the obligations of Debtor under this Agreement shall remain in
full force and effect without regard to, and shall not be impaired or affected
by:

         (a)     any amendment or modification or addition or supplement to any
Loan Documents or any instrument delivered in connection therewith or any
assignment or transfer thereof;

         (b)     any exercise, non-exercise, or waiver by Administrative Agent
or any Secured Party of any right, remedy, power or privilege under or in
respect of, or any release of any guaranty or the Collateral or any part
thereof provided pursuant to, this Agreement or any Loan Documents;

         (c)     any waiver, consent, extension, indulgence or other action or
inaction in respect of this Agreement, any Loan Documents or any assignment or
transfer of any thereof; or

         (d)     any bankruptcy, insolvency, reorganization, arrangement,
readjustment, composition, liquidation or the like of Debtor or any other
Person, whether or not Debtor shall have notice or knowledge of any of the
foregoing.





                                     - 12 -
<PAGE>   16
         6.19.   ENTIRE AGREEMENT.  THIS WRITTEN AGREEMENT, TOGETHER WITH THE
OTHER LOAN DOCUMENTS, REPRESENT THE FINAL AGREEMENT BETWEEN THE PARTIES AND MAY
NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS, OR SUBSEQUENT ORAL
AGREEMENTS OF THE PARTIES.  THERE ARE NO UNWRITTEN ORAL ARGUMENTS BETWEEN THE
PARTIES.


                   REMAINDER OF PAGE LEFT INTENTIONALLY BLANK





                                     - 13 -
<PAGE>   17
         IN WITNESS WHEREOF, the parties hereto have caused this Agreement to
be executed by their duly authorized officers or members all as of the date
first above written.

                                        DEBTOR:

                                        XIRCOM, INC.
2300 Corporate Center Drive
Thousand Oaks, California 91320
Telecopier No.:  (805) 376-9120
Telephone No.:  (805) 376-9300          By:  [SIG]
                                             -----------------------------
                                             Name:  Randall H. Holliday
                                                    ----------------------
Attention: Chief Financial Officer           Title: Secretary
                                                    ----------------------

                                        SECURED PARTY:

                                        NATIONSBANK OF TEXAS, N.A., as
                                        Administrative Agent



                                        By:  [SIG]
                                             -----------------------------
                                             Name:  William C. Collins
                                                    ----------------------
                                             Title: Sr. Vice President
                                                    ----------------------












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