<PAGE>
 
                                                                    Exhibit 4.17

THIS WARRANT HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
AMENDED, OR THE SECURITIES LAWS OF ANY STATE AND MAY NOT BE SOLD, TRANSFERRED OR
OTHERWISE DISPOSED OF EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT OR
EXEMPTION FROM REGISTRATION UNDER THE FOREGOING LAWS. ACCORDINGLY, THIS WARRANT
MAY NOT BE SOLD, TRANSFERRED OR OTHERWISE DISPOSED OF WITHOUT (I) AN OPINION OF
COUNSEL SATISFACTORY TO ANCOR COMMUNICATIONS, INCORPORATED THAT SUCH SALE,
TRANSFER OR OTHER DISPOSITION MAY LAWFULLY BE MADE WITHOUT REGISTRATION UNDER
THE SECURITIES ACT OF 1933 AND APPLICABLE STATE SECURITIES LAWS OR (II) SUCH
REGISTRATION.


                       ANCOR COMMUNICATIONS, INCORPORATED

                                     WARRANT
                                   TO PURCHASE
                             SHARES OF COMMON STOCK


         For value received, INRANGE Technologies Corporation, its successors or
assigns ("Holder"), is entitled to purchase from Ancor Communications,
Incorporated, a Minnesota corporation (the "Company"), up to 750,000 fully paid
and nonassessable shares of the Company's common stock, $.01 par value per
share, or such greater or lesser number of such shares as may be determined by
application of the anti-dilution provisions of this warrant, 250,000 of which
may be purchased at a price of $2.50 per share, 250,000 of which may be
purchased at a price of $5.00 per share and 250,000 of which may be purchased at
the price of $10.00 per share, all subject to adjustments as noted below
(individually or in the aggregate, the "warrant exercise price").

         This warrant may be exercised by Holder at any time or from time to
time beginning on March 24, 1999, prior to the close of business on September
24, 2003, provided, however, that this warrant may not be exercised and shall
not be effective unless and until the Technology License Agreement between the
Company and Holder dated September 24, 1998 shall become effective pursuant to
the terms thereof.

         This warrant is subject to the following terms and conditions:

         1. Exercise. The rights represented by this warrant may be exercised by
the Holder, in whole or in part, by written election, in the form set forth
below, by the surrender of this warrant (properly endorsed if required) at the
principal office of the Company, by payment to it by cash, certified check or
bank draft of the applicable warrant exercise price for the shares to be
purchased and by delivery of a subscription agreement, an investment letter
and/or similar documents acceptable to the Company demonstrating that the sale
of the shares to be purchased is exempt from registration under the Securities
Act of 1933, as amended, and any state securities law. The shares so purchased
shall be deemed to be issued as of the close of business on the date on which
this warrant has been exercised by payment to the Company of the warrant
exercise price. Certificates for the shares of stock so purchased, bearing an
appropriate restrictive legend, shall be delivered to the Holder within 15 days
after the rights represented by this warrant shall have been so exercised, and,
unless this warrant has expired, a new warrant representing the number of
shares, if any, with respect to which this warrant has not been exercised shall
also be delivered to the Holder hereof within such time. No fractional shares
shall be issued upon the exercise of this warrant.
<PAGE>
 
         2. Shares. All shares that may be issued upon the exercise of the
rights represented by this warrant shall, upon issuance, be duly authorized and
issued, fully paid and nonassessable shares. During the period within which the
rights represented by this warrant may be exercised, the Company shall at all
times have authorized and reserved for the purpose of issue or transfer upon
exercise of the subscription rights evidenced by this warrant a sufficient
number of shares of its common stock to provide for the exercise of the rights
represented by this warrant.

         3. Adjustment. The warrant exercise price shall be subject to
adjustment from time to time as hereinafter provided in this Section 3:

                  (a) If the Company at any time divides the outstanding shares
         of its common stock into a greater number of shares (whether pursuant
         to a stock split, stock dividend or otherwise), and conversely, if the
         outstanding shares of its common stock are combined into a smaller
         number of shares, the warrant exercise price(s) in effect immediately
         prior to such division or combination shall be proportionately adjusted
         to reflect the reduction or increase in the value of each such common
         share.

                  (b) If any capital reorganization or reclassification of the
         capital stock of the Company, or consolidation or merger of the Company
         with another corporation, or the sale of all or substantially all of
         its assets to another corporation shall be effected in such a way that
         holders of the Company's common stock shall be entitled to receive
         stock, securities or assets with respect to or in exchange for such
         common stock, then, as a condition of such reorganization,
         reclassification, consolidation, merger or sale, the Holder shall have
         the right to purchase and receive upon the basis and upon the terms and
         conditions specified in this warrant and in lieu of the shares of the
         common stock of the Company immediately theretofore purchasable and
         receivable upon the exercise of the rights represented hereby, such
         shares of stock, other securities or assets as would have been issued
         or delivered to the Holder if Holder had exercised this warrant and had
         received such shares of common stock immediately prior to such
         reorganization, reclassification, consolidation, merger or sale. The
         Company shall not effect any such consolidation, merger or sale unless
         prior to the consummation thereof the successor corporation (if other
         than the Company) resulting from such consolidation or merger or the
         corporation purchasing such assets shall assume by written instrument
         the obligation to deliver to the Holder such shares of stock,
         securities or assets as, in accordance with the foregoing provisions,
         the Holder may be entitled to purchase.

                  (c) If the Company takes any other action, or if any other
         event occurs, which does not come within the scope of the provisions of
         Section 3(a) or 3(b), but which should result in an adjustment in the
         applicable warrant exercise price(s) and/or the number of shares
         subject to this warrant in order to fairly protect the purchase rights
         of the Holder, an appropriate adjustment in such purchase rights shall
         be made by the Company.

                  (d) Upon each adjustment of the warrant exercise price(s), the
         Holder shall thereafter be entitled to purchase, at the warrant
         exercise price(s) resulting from such adjustment, the sum of the number
         of shares obtained by multiplying each warrant exercise price in effect
         immediately prior to such adjustment by the number of shares
         purchasable pursuant hereto at such exercise price immediately prior to
         such adjustment and dividing the product thereof by the corresponding
         new warrant exercise price resulting from such adjustment. 

                                      -2-
<PAGE>
 
         4. No Rights as Shareholder. This warrant shall not entitle the Holder
to any voting rights or other rights as a shareholder of the Company.

         5. Transfer. This Warrant may not be sold, transferred or otherwise
disposed of without (i) an opinion of counsel satisfactory to the Company that
such sale, transfer or other disposition may lawfully be made without
registration under the securities act of 1933 and applicable state securities
laws or (ii) such registration. Subject to the foregoing, this warrant and all
rights hereunder are transferable, in whole or in part, at the principal office
of the Company by the holder hereof in person or by duly authorized attorney,
upon surrender of this warrant properly endorsed. The bearer of this warrant,
when endorsed, may be treated by the Company and all other persons dealing with
this warrant as the absolute owner hereof for any purpose and as the person
entitled to exercise the rights represented by this warrant, or to the transfer
hereof on the books of the Company, any notice to the contrary notwithstanding;
but until such transfer on such books, the Company may treat the registered
owner hereof as the owner for all purposes.

         6. Registration Rights. Holder shall be entitled to the registration
rights set forth on Exhibit A to this warrant.

         7. Writing. This warrant may not be changed, waived, discharged or
terminated orally but only by an instrument in writing signed by the party
against which enforcement of the change, waiver, discharge or termination is
sought.

         IN WITNESS WHEREOF, the Company has caused this warrant to be executed
and delivered by a duly authorized officer.

Dated: September 24, 1998


                                         ANCOR COMMUNICATIONS, INCORPORATED



                                         By /s/ Calvin G. Nelson
                                            ------------------------------
                                            Calvin G. Nelson
                                            President


Name and Address of Holder:

INRANGE Technologies Corporation
13000 Midlantic Drive
Mt. Laurel, New Jersey 08054

                                      -3-
<PAGE>
 
                                WARRANT EXERCISE

                (To be signed only upon exercise of this warrant)

         The undersigned, the Holder of the foregoing warrant, hereby
irrevocably elects to exercise the purchase right represented by such warrant
for, and to purchase thereunder, a total of shares of common stock of Ancor
Communications, Incorporated, to which such warrant relates and herewith makes
payment of $ _____________ therefor in cash, certified check or bank draft and
requests that the certificates for such shares be issued in the name of, and be
delivered to ________________________ , whose address is set forth below the
signature of the undersigned. The number of shares to be purchased at each
exercise price is as follows:

             Number of Shares                   Purchase Price
             ----------------                   --------------
             ________________                   $_____________                  
             ________________                   $_____________                  
             ________________                   $_____________                  

Dated:___________________                                 

                                         --------------------------------
                                         Signature


Social Security or other Tax Identification No.
__________________________

If shares are to be issued other than to Holder:

Please print present name and complete address

__________________________

__________________________

                                      -4-
<PAGE>
 
                               WARRANT ASSIGNMENT

                (To be signed only upon transfer of this warrant)

         FOR VALUE RECEIVED, the undersigned hereby sells, assigns and transfers
unto ______________ the right represented by the foregoing warrant to purchase
the shares of common stock of Ancor Communications, Incorporated and appoints
________________ attorney to transfer such right on the books of Ancor
Communications, Incorporated, with full power of substitution in the premises.

Dated:____________                                 

                                         ------------------------------
                                         Signature


Social Security or other Tax Identification No.
______________________________


Please print present name and complete address

______________________________

______________________________

                                      -5-
<PAGE>
 
                                                                       EXHIBIT A


                         REGISTRATION RIGHTS DECLARATION


         1. Registration Rights.

         a. Demand Registration. If at any one time prior to September 24, 2004
the Company shall receive a written request from the registered holder to which
this declaration is attached or the registered holder of Common Stock acquired
upon exercise of such instrument ("Holder") to register shares of Company common
stock ("Registrable Securities") that have been or may be acquired by Holder
pursuant to the exercise or conversion of the instrument to which this
declaration is attached and which are not otherwise eligible for resale without
volume limitation pursuant to Rule 144 under the Securities Act of 1933, as
amended ("Rule 144"), the Company shall promptly prepare and file a registration
statement under the Securities Act covering the number of Registrable Securities
which are the subject of such requests and shall use reasonable efforts to cause
such registration statement to become effective The Company shall cause such
registration statement to remain effective until the earlier to occur of the
following: (i) all shares subject to the registration have been sold in
accordance with the terms thereof, (ii) all of the shares are able to be sold
without volume limitation pursuant to Rule 144 or (iii) the later of six months
following the effective date or September 24, 2004. In the event that the
original instrument to which this declaration is attached is subsequently held
by more than one person or entity, the right under this Section may be exercised
by the person(s) or entity(s) holding in excess of 50% of the original
instrument and any other Holder shall be entitled to notice of and to
participate in the registration.

         If, at any time that the Company is required to file a registration
statement hereunder, or any such registration statement is effective, the Board
of Directors of the Company determines, in good faith, that a sale of Common
Stock pursuant to the registration statement would require disclosure of
material information which the Company has a bona fide business purpose for
preserving as confidential, the Company shall not be required to file such
registration statement, or may suspend the effectiveness of an effective
registration statement, during the time such restriction is advisable; provided,
however, that the delay in filing of such registration statement or the
suspension of effectiveness of such registration statement shall not exceed a
period of 120 consecutive days. In the event the effectiveness of a registration
statement is suspended, the time that the Company is required to keep such
registration statement effective shall be extended by the number of days the
effectiveness of such registration statement was suspended.

         (b). Piggyback Registration Rights. Each time prior to September 24,
2004 that the Company shall determine to proceed with the actual preparation and
filing of a registration statement under the Securities Act of 1933, as amended
(the "Securities Act"), in connection with the proposed offer and sale for money
of any of its securities by it (other than a registration on Form S-8 or a
successor form), the Company will give written notice of its determination to
Holder. Upon the written request of Holder given within 15 days after receipt of
any such notice 

                                      -6-
<PAGE>
 
from the Company, the Company will, except as herein provided, cause all shares
of Company common stock that have been or may be acquired by Holder pursuant to
the exercise or conversion of the instrument to which this declaration is
attached and with respect to which Holder has requested registration to be
included in such registration statement, all to the extent requisite to permit
the sale or other disposition by Holder of the shares to be so registered;
provided, however, that nothing herein shall prevent the Company from, at any
time, abandoning or delaying any such registration initiated by it. If any such
registration pertains to an underwritten offering in whole or in part, the
Company may require that the shares requested for inclusion by Holder pursuant
to this section be included in the underwritten offering on the same terms and
conditions as the securities otherwise being sold through the underwriters. In
the event that if in the good faith judgment of the managing underwriter of such
underwritten offering the inclusion of all of the shares originally covered by a
request for registration made by Holder would reduce the amount of securities to
be offered by the Company or interfere with the successful marketing of the
securities to be offered by the Company, the number of shares of stock owned by
Holder and otherwise to be included in the underwritten offering may be reduced;
provided, however, that any such required reduction shall be pro rata among all
persons (other than the Company) who are participating in such underwritten
offering to the extent not inconsistent with registration rights granted by the
Company to others prior to the date hereof. Those shares which are thus excluded
from the underwritten offering shall be withheld from the market by Holder for a
period, not to exceed 180 days, that the managing underwriter reasonably
determines is necessary in order to effect the underwritten offering.

         2. Registration Procedures. If and whenever the Company is required by
the provisions of Section 1 to effect the registration of any shares under the
Securities Act, the Company will:

                  (a) prepare and file with the Commission a registration
         statement with respect to such shares, and use its best efforts to
         cause such registration statement to become and remain effective for
         such period as is specified in paragraph 1(a) hereof with respect to
         registrations effected pursuant to paragraph 1(a) and for such period
         as may be reasonably necessary to effect the sale of such shares, not
         to exceed three months, with respect to registrations effected pursuant
         to paragraph 1(b);

                  (b) prepare and file with the Commission such amendments to
         such registration statement and supplements to the prospectus contained
         therein as may be necessary to keep such registration statement
         effective for such period as is specified in paragraph 1(a) hereof with
         respect to registrations effected pursuant to paragraph 1(a) and for
         such period as may be reasonably necessary to effect the sale of such
         shares, not to exceed three months, with respect to registrations
         effected pursuant to paragraph 1(b);

                  (c) furnish to Holder and to the underwriters of the
         securities being registered such reasonable number of copies of the
         registration statement, preliminary prospectus, final prospectus and
         such other documents as Holder and underwriters may reasonably request
         in order to facilitate the public offering of such securities;

                                      -7-
<PAGE>
 
                  (d) prepare and promptly file with the Commission and promptly
         notify Holder of the filing of such amendment or supplement to such
         registration statement or prospectus as may be necessary to correct any
         statements or omissions if, at the time when a prospectus relating to
         such securities is required to be delivered under the Securities Act,
         any event shall have occurred as the result of which any such
         prospectus or any other prospectus as then in effect would include an
         untrue statement of a material fact or omit to state any material fact
         necessary to make the statements therein, in the light of the
         circumstances in which they were made, not misleading.

         3. Expenses. With respect to any registration of shares pursuant to
Section 1, the Company shall bear the following fees, costs and expenses: all
registration, filing and NASD fees, printing expenses, fees and disbursements of
counsel and accountants for the Company, fees and disbursements of counsel for
the underwriter or underwriters of such securities (if the Company and/or
selling security holders are required to bear such fees and disbursements), all
internal Company expenses, the premiums and other costs of policies of insurance
against liability arising out of the public offering, and all legal fees and
disbursements and other expenses of complying with state securities or blue sky
laws of any jurisdictions in which the securities to be offered are to be
registered or qualified. Fees and disbursements of counsel and accountants for
Holder, underwriting discounts and commissions and transfer taxes for Holder and
any other expenses incurred by Holder not expressly included above shall be
borne by Holder.

         4. Indemnification. In the event that any shares owned by Holder are
included in a registration statement under Section 1:

                  (a) The Company will indemnify and hold harmless Holder and
         any underwriter (as defined in the Securities Act) for Holder from and
         against any and all loss, damage, liability, cost and expense to which
         Holder or any such underwriter may become subject under the Securities
         Act or otherwise, insofar as such losses, damages, liabilities, costs
         or expenses are caused by any untrue statement or alleged untrue
         statement of any material fact contained in such registration
         statement, any prospectus contained therein or any amendment or
         supplement thereto, or arise out of or are based upon the omission or
         alleged omission to state therein a material fact required to be stated
         therein or necessary to make the statements therein, in light of the
         circumstances in which they were made, not misleading; provided,
         however, that the Company will not be liable in any such case to the
         extent that any such loss, damage, liability, cost or expense arises
         out of or is based upon an untrue statement or alleged untrue statement
         or omission or alleged omission so made in conformity with information
         furnished by Holder or such underwriter.

                  (b) Holder will indemnify and hold harmless the Company and
         any underwriter from and against any and all loss, damage, liability,
         cost or expense to which the Company or any underwriter may become
         subject under the Securities Act or otherwise, insofar as such losses,
         damages, liabilities, costs or expenses are caused by any 

                                      -8-
<PAGE>
 
         untrue or alleged untrue statement of any material fact contained in
         such registration statement, any prospectus contained therein or any
         amendment or supplement thereto, or arise out of or are based upon the
         omission or the alleged omission to state therein a material fact
         required to be stated therein or necessary to make the statements
         therein, in light of the circumstances in which they were made, not
         misleading, in each case to the extent, but only to the extent, that
         such untrue statement or alleged untrue statement or omission or
         alleged omission was so made in reliance upon and in strict conformity
         with information furnished by Holder.

                  (c) Promptly after receipt by an indemnified party pursuant to
         the provisions of paragraph (a) or (b) of this section of notice of the
         commencement of any action involving the subject matter of the
         foregoing indemnity provisions, such indemnified party will, if a claim
         thereof is to be made against the indemnifying party pursuant to the
         provisions of said paragraph (a) or (b), promptly notify the
         indemnifying party of the commencement thereof; but the omission to so
         notify the indemnifying party will not relieve it from any liability
         which it may have to any indemnified party otherwise than hereunder. In
         case such action is brought against any indemnified party and it
         notifies the indemnifying party of the commencement thereof, the
         indemnifying party shall have the right to participate in, and, to the
         extent that it may wish, jointly with any other indemnifying party
         similarly notified, to assume the defense thereof, with counsel
         satisfactory to such indemnified party; provided, however, if the
         defendants in any action include both the indemnified party and the
         indemnifying party and there is a conflict of interest which would
         prevent counsel for the indemnifying party from also representing the
         indemnified party, the indemnified party or parties shall have the
         right to select separate counsel to participate in the defense of such
         action on behalf of such indemnified party or parties. After notice
         from the indemnifying party to such indemnified party of its election
         so to assume the defense thereof, the indemnifying party will not be
         liable to such indemnified party pursuant to the provisions of
         paragraph (a) or (b) for any legal or other expense subsequently
         incurred by such indemnified party in connection with the defense
         thereof other than reasonable costs of investigation, unless (i) the
         indemnified party shall have employed counsel in accordance with the
         proviso of the preceding sentence, (ii) the indemnifying party shall
         not have employed counsel satisfactory to the indemnified party to
         represent the indemnified party within a reasonable time after the
         notice of the commencement of the action or (iii) the indemnifying
         party has authorized the employment of counsel for the indemnified
         party at the expense of the indemnifying party.

         5. Rule 144. The Company covenants and agrees to use reasonable efforts
to file such reports and/or make available such information as is required in
order for Rule 144 to be available to Holder at any time that Holder would
otherwise be eligible to sell pursuant to Rule 144.

                                      -9-