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                                                                    Exhibit 10.1

                      BROCADE COMMUNICATIONS SYSTEMS, INC.

                            1999 DIRECTOR OPTION PLAN

                    AMENDED AND RESTATED AS OF APRIL 17, 2001


       1. Purposes of the Plan. The purposes of this 1999 Director Option Plan
are to attract and retain the best available personnel for service as Outside
Directors (as defined herein) of the Company, to provide additional incentive to
the Outside Directors of the Company to serve as Directors, and to encourage
their continued service on the Board.

              All options granted hereunder shall be nonstatutory stock options.

       2. Definitions. As used herein, the following definitions shall apply:

              (a) "Board" means the Board of Directors of the Company.

              (b) "Code" means the Internal Revenue Code of 1986, as amended.

              (c) "Common Stock" means the common stock of the Company.

              (d) "Company" means Brocade Communications Systems, Inc., a
Delaware corporation.

              (e) "Director" means a member of the Board.

              (f) "Disability" means total and permanent disability as defined
in section 22(e)(3) of the Code.

              (g) "Employee" means any person, including officers and Directors,
employed by the Company or any Parent or Subsidiary of the Company. The payment
of a Director's fee by the Company shall not be sufficient in and of itself to
constitute "employment" by the Company.

              (h) "Exchange Act" means the Securities Exchange Act of 1934, as
amended.

              (i) "Fair Market Value" means, as of any date, the value of Common
Stock determined as follows:

                     (i) If the Common Stock is listed on any established stock
exchange or a national market system, including without limitation the Nasdaq
National Market or The Nasdaq SmallCap Market of The Nasdaq Stock Market, its
Fair Market Value shall be the closing sales price for such stock (or the
closing bid, if no sales were reported) as quoted on such exchange or system


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for the last market trading day prior to the time of determination as reported
in The Wall Street Journal or such other source as the Administrator deems
reliable;

                     (ii) If the Common Stock is regularly quoted by a
recognized securities dealer but selling prices are not reported, the Fair
Market Value of a Share of Common Stock shall be the mean between the high bid
and low asked prices for the Common Stock for the last market trading day prior
to the time of determination, as reported in The Wall Street Journal or such
other source as the Board deems reliable; or

                     (iii) In the absence of an established market for the
Common Stock, the Fair Market Value thereof shall be determined in good faith by
the Board.

              (j) "Inside Director" means a Director who is an Employee.

              (k) "Option" means a stock option granted pursuant to the Plan.

              (l) "Optioned Stock" means the Common Stock subject to an Option.

              (m) "Optionee" means a Director who holds an Option.

              (n) "Outside Director" means a Director who is not an Employee.

              (o) "Parent" means a "parent corporation," whether now or
hereafter existing, as defined in Section 424(e) of the Code.

              (p) "Plan" means this 1999 Director Option Plan.

              (q) "Share" means a share of the Common Stock, as adjusted in
accordance with Section 10 of the Plan.

              (r) "Subsidiary" means a "subsidiary corporation," whether now or
hereafter existing, as defined in Section 424(f) of the Internal Revenue Code of
1986.

       3. Stock Subject to the Plan. Subject to the provisions of Section 10 of
the Plan, the maximum aggregate number of Shares which may be optioned and sold
under the Plan is 1,600,000 Shares (the "Pool"). The Shares may be authorized,
but unissued, or reacquired Common Stock.

              If an Option expires or becomes unexercisable without having been
exercised in full, the unpurchased Shares which were subject thereto shall
become available for future grant or sale under the Plan (unless the Plan has
terminated). Shares that have actually been issued under the Plan shall not be
returned to the Plan and shall not become available for future distribution
under the Plan.


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       4. Administration and Grants of Options under the Plan.

              (a) Procedure for Grants. All grants of Options to Outside
Directors under this Plan shall be automatic and nondiscretionary and shall be
made strictly in accordance with the following provisions; provided, however,
that the Board may, in its sole discretion, provide that certain Outside
Directors are not eligible to receive grants of Options for specified periods of
time.

                     (i) No person shall have any discretion to select which
Outside Directors shall be granted Options or to determine the number of Shares
to be covered by Options.

                     (ii) Each Outside Director shall be automatically granted
an Option to purchase 80,000 shares (the "First Option") on the date on which
such person first becomes an Outside Director, whether through election by the
shareholders of the Company or appointment by the Board to fill a vacancy;
provided, however, that an Inside Director who ceases to be an Inside Director
but who remains a Director shall not receive a First Option.

                     (iii) Neal Dempsey and Seth Neiman shall each be granted an
Option to purchase 80,000 shares on April 17, 2001 (the "Dempsey and Neiman
Interim Options").

                     (iv) Larry Sonsini and Mark Leslie shall each be granted an
Option to purchase 60,000 shares on April 17, 2001 (the "Sonsini and Leslie
Interim Options").

                     (iv) Each Outside Director shall be automatically granted
an Option to purchase 20,000 shares (a "Subsequent Option") on each anniversary
of their becoming an Outside Director, provided he or she is then an Outside
Director; provided, however, that commencing upon April 17, 2002, Neal Dempsey,
Seth Neiman, Larry Sonsini and Mark Leslie shall have their Subsequent Options
granted on April 17 of every year instead of on their anniversary of becoming an
Outside Director, so long as they remain an Outside Director through the dates
of such grants.

                     (v) The terms of a First Option granted hereunder shall be
as follows:

                            (A) the term of the First Option shall be ten (10)
years.

                            (B) the First Option shall be exercisable only while
the Outside Director remains a Director of the Company, except as set forth in
Sections 8 and 10 hereof.

                            (C) the exercise price per Share shall be 100% of
the Fair Market Value per Share on the date of grant of the First Option.

                            (D) subject to Section 10 hereof, the First Option
shall become exercisable as to one-sixteenth of the Shares subject to the First
Option each three months following its date of grant, so as to become 100%
vested on the fourth anniversary of the date of grant, provided that the
Optionee continues to serve as a Director on such dates.


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                     (vi) The terms of the Dempsey and Neiman Interim Options
granted hereunder shall be as follows:

                            (A) the term of the Dempsey and Neiman Interim
Options shall be ten (10) years.

                            (B) the Dempsey and Neiman Interim Options shall be
exercisable only while the Outside Director remains a Director of the Company,
except as set forth in Sections 8 and 10 hereof.

                            (C) the exercise price per Share shall be 100% of
the Fair Market Value per Share on the date of grant of the Dempsey and Neiman
Interim Options.

                            (D) subject to Section 10 hereof, the Dempsey and
Neiman Interim Options shall become exercisable as to one-sixteenth of the
Shares subject to the Dempsey and Neiman Interim Options each three months
following the date of grant, so as to become 100% vested on the fourth
anniversary of the date of grant, provided that the Optionee continues to serve
as a Director on such dates.

                     (vii) The terms of the Sonsini and Leslie Interim Options
granted hereunder shall be as follows:

                            (A) the term of the Sonsini and Leslie Interim
Options shall be ten (10) years.

                            (B) the Sonsini and Leslie Options shall be
exercisable only while the Outside Director remains a Director of the Company,
except as set forth in Sections 8 and 10 hereof.

                            (C) the exercise price per Share shall be 100% of
the Fair Market Value per Share on the date of grant of the Sonsini and Leslie
Interim Options.

                            (D) subject to Section 10 hereof, commencing on the
first anniversary of the date of grant, the Sonsini and Leslie Options shall
become exercisable as to one-twelfth of the Shares subject to the Sonsini and
Leslie Interim Options each three months thereafter, so as to become 100% vested
on the fourth anniversary of the date of grant, provided that the Optionee
continues to serve as a Director on such dates.

                     (viii) The terms of a Subsequent Option granted hereunder
shall be as follows:

                            (A) the term of the Subsequent Option shall be ten
(10) years.

                            (B) the Subsequent Option shall be exercisable only
while the Outside Director remains a Director of the Company, except as set
forth in Sections 8 and 10 hereof.


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                            (C) the exercise price per Share shall be 100% of
the Fair Market Value per Share on the date of grant of the Subsequent Option.

                            (D) subject to Section 10 hereof, commencing on the
third anniversary of the date of grant, the Subsequent Option shall become
exercisable as to one-fourth of the Shares subject to the Subsequent Option each
three months following such anniversary, so as to become 100% vested on the
fourth anniversary of the date of grant, provided that the Optionee continues to
serve as a Director on such dates.

                     (ix) In the event that any Option granted under the Plan
would cause the number of Shares subject to outstanding Options plus the number
of Shares previously purchased under Options to exceed the Pool, then the
remaining Shares available for Option grant shall be granted under Options to
the Outside Directors on a pro rata basis. No further grants shall be made until
such time, if any, as additional Shares become available for grant under the
Plan through action of the Board or the shareholders to increase the number of
Shares which may be issued under the Plan or through cancellation or expiration
of Options previously granted hereunder.

       5. Eligibility. Options may be granted only to Outside Directors. All
Options shall be automatically granted in accordance with the terms set forth in
Section 4 hereof.

              The Plan shall not confer upon any Optionee any right with respect
to continuation of service as a Director or nomination to serve as a Director,
nor shall it interfere in any way with any rights which the Director or the
Company may have to terminate the Director's relationship with the Company at
any time.

       6. Term of Plan. The Plan shall become effective upon the earlier to
occur of its adoption by the Board or its approval by the shareholders of the
Company as described in Section 16 of the Plan. It shall continue in effect for
a term of ten (10) years unless sooner terminated under Section 11 of the Plan.

       7. Form of Consideration. The consideration to be paid for the Shares to
be issued upon exercise of an Option, including the method of payment, shall
consist of (i) cash, (ii) check, (iii) other shares which (x) in the case of
Shares acquired upon exercise of an option, have been owned by the Optionee for
more than six (6) months on the date of surrender, and (y) have a Fair Market
Value on the date of surrender equal to the aggregate exercise price of the
Shares as to which said Option shall be exercised, (iv) consideration received
by the Company under a cashless exercise program implemented by the Company in
connection with the Plan, or (v) any combination of the foregoing methods of
payment.


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       8. Exercise of Option.

              (a) Procedure for Exercise; Rights as a Shareholder. Any Option
granted hereunder shall be exercisable at such times as are set forth in Section
4 hereof; provided, however, that no Options shall be exercisable until
shareholder approval of the Plan in accordance with Section 16 hereof has been
obtained.

              An Option may not be exercised for a fraction of a Share.

              An Option shall be deemed to be exercised when written notice of
such exercise has been given to the Company in accordance with the terms of the
Option by the person entitled to exercise the Option and full payment for the
Shares with respect to which the Option is exercised has been received by the
Company. Full payment may consist of any consideration and method of payment
allowable under Section 7 of the Plan. Until the issuance (as evidenced by the
appropriate entry on the books of the Company or of a duly authorized transfer
agent of the Company) of the stock certificate evidencing such Shares, no right
to vote or receive dividends or any other rights as a shareholder shall exist
with respect to the Optioned Stock, notwithstanding the exercise of the Option.
A share certificate for the number of Shares so acquired shall be issued to the
Optionee as soon as practicable after exercise of the Option. No adjustment
shall be made for a dividend or other right for which the record date is prior
to the date the stock certificate is issued, except as provided in Section 10 of
the Plan.

              Exercise of an Option in any manner shall result in a decrease in
the number of Shares which thereafter may be available, both for purposes of the
Plan and for sale under the Option, by the number of Shares as to which the
Option is exercised.

              (b) Termination of Continuous Status as a Director. Subject to
Section 10 hereof, in the event an Optionee's status as a Director terminates
(other than upon the Optionee's death or Disability), the Optionee may exercise
his or her Option, but only within three (3) months following the date of such
termination, and only to the extent that the Optionee was entitled to exercise
it on the date of such termination (but in no event later than the expiration of
its ten (10) year term). To the extent that the Optionee was not entitled to
exercise an Option on the date of such termination, and to the extent that the
Optionee does not exercise such Option (to the extent otherwise so entitled)
within the time specified herein, the Option shall terminate.

              (c) Disability of Optionee. In the event Optionee's status as a
Director terminates as a result of Disability, the Optionee may exercise his or
her Option, but only within twelve (12) months following the date of such
termination, and only to the extent that the Optionee was entitled to exercise
it on the date of such termination (but in no event later than the expiration of
its ten (10) year term). To the extent that the Optionee was not entitled to
exercise an Option on the date of termination, or if he or she does not exercise
such Option (to the extent otherwise so entitled) within the time specified
herein, the Option shall terminate.

              (d) Death of Optionee. In the event of an Optionee's death, the
Optionee's estate or a person who acquired the right to exercise the Option by
bequest or inheritance may exercise the


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Option, but only within twelve (12) months following the date of death, and only
to the extent that the Optionee was entitled to exercise it on the date of death
(but in no event later than the expiration of its ten (10) year term). To the
extent that the Optionee was not entitled to exercise an Option on the date of
death, and to the extent that the Optionee's estate or a person who acquired the
right to exercise such Option does not exercise such Option (to the extent
otherwise so entitled) within the time specified herein, the Option shall
terminate.

       9. Non-Transferability of Options. The Option may not be sold, pledged,
assigned, hypothecated, transferred, or disposed of in any manner other than by
will or by the laws of descent or distribution and may be exercised, during the
lifetime of the Optionee, only by the Optionee.

       10. Adjustments Upon Changes in Capitalization, Dissolution, Merger or
Asset Sale.

              (a) Changes in Capitalization. Subject to any required action by
the shareholders of the Company, the number of Shares covered by each
outstanding Option, the number of Shares which have been authorized for issuance
under the Plan but as to which no Options have yet been granted or which have
been returned to the Plan upon cancellation or expiration of an Option, as well
as the price per Share covered by each such outstanding Option shall be
proportionately adjusted for any increase or decrease in the number of issued
Shares resulting from a stock split, reverse stock split, stock dividend,
combination or reclassification of the Common Stock, or any other increase or
decrease in the number of issued Shares effected without receipt of
consideration by the Company; provided, however, that conversion of any
convertible securities of the Company shall not be deemed to have been "effected
without receipt of consideration;" provided, further, that the number of Shares
subject to subsequently granted First Options and Subsequent Options shall not
be proportionately adjusted. Except as expressly provided herein, no issuance by
the Company of shares of stock of any class, or securities convertible into
shares of stock of any class, shall affect, and no adjustment by reason thereof
shall be made with respect to, the number or price of Shares subject to an
Option.

              (b) Dissolution or Liquidation. In the event of the proposed
dissolution or liquidation of the Company, to the extent that an Option has not
been previously exercised, it shall terminate immediately prior to the
consummation of such proposed action.

              (c) Merger or Asset Sale. In the event of a merger of the Company
with or into another corporation or the sale of substantially all of the assets
of the Company, outstanding Options may be assumed or equivalent options may be
substituted by the successor corporation or a Parent or Subsidiary thereof (the
"Successor Corporation"). If an Option is assumed or substituted for, the Option
or equivalent option shall continue to be exercisable as provided in Section 4
hereof for so long as the Optionee serves as a Director or a director of the
Successor Corporation. Following such assumption or substitution, if the
Optionee's status as a Director or director of the Successor Corporation, as
applicable, is terminated other than upon a voluntary resignation by the
Optionee, the Option or option shall become fully exercisable, including as to
Shares for which it would not otherwise be exercisable. Thereafter, the Option
or option shall remain exercisable in accordance with Sections 8(b) through (d)
above.


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       If the Successor Corporation does not assume an outstanding Option or
substitute for it an equivalent option, the Option shall become fully vested and
exercisable, including as to Shares for which it would not otherwise be
exercisable. In such event the Board shall notify the Optionee that the Option
shall be fully exercisable for a period of thirty (30) days from the date of
such notice, and upon the expiration of such period the Option shall terminate.

       For the purposes of this Section 10(c), an Option shall be considered
assumed if, following the merger or sale of assets, the Option confers the right
to purchase or receive, for each Share of Optioned Stock subject to the Option
immediately prior to the merger or sale of assets, the consideration (whether
stock, cash, or other securities or property) received in the merger or sale of
assets by holders of Common Stock for each Share held on the effective date of
the transaction (and if holders were offered a choice of consideration, the type
of consideration chosen by the holders of a majority of the outstanding Shares).
If such consideration received in the merger or sale of assets is not solely
common stock of the successor corporation or its Parent, the Administrator may,
with the consent of the successor corporation, provide for the consideration to
be received upon the exercise of the Option, for each Share of Optioned Stock
subject to the Option, to be solely common stock of the successor corporation or
its Parent equal in fair market value to the per share consideration received by
holders of Common Stock in the merger or sale of assets.

       11. Amendment and Termination of the Plan.

              (a) Amendment and Termination. The Board may at any time amend,
alter, suspend, or discontinue the Plan, but no amendment, alteration,
suspension, or discontinuation shall be made which would impair the rights of
any Optionee under any grant theretofore made, without his or her consent. In
addition, to the extent necessary and desirable to comply with any applicable
law, regulation or stock exchange rule, the Company shall obtain shareholder
approval of any Plan amendment in such a manner and to such a degree as
required.

              (b) Effect of Amendment or Termination. Any such amendment or
termination of the Plan shall not affect Options already granted and such
Options shall remain in full force and effect as if this Plan had not been
amended or terminated.

       12. Time of Granting Options. The date of grant of an Option shall, for
all purposes, be the date determined in accordance with Section 4 hereof.

       13. Conditions Upon Issuance of Shares. Shares shall not be issued
pursuant to the exercise of an Option unless the exercise of such Option and the
issuance and delivery of such Shares pursuant thereto shall comply with all
relevant provisions of law, including, without limitation, the Securities Act of
1933, as amended, the Exchange Act, the rules and regulations promulgated
thereunder, state securities laws, and the requirements of any stock exchange
upon which the Shares may then be listed, and shall be further subject to the
approval of counsel for the Company with respect to such compliance.

              As a condition to the exercise of an Option, the Company may
require the person exercising such Option to represent and warrant at the time
of any such exercise that the Shares are


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being purchased only for investment and without any present intention to sell or
distribute such Shares, if, in the opinion of counsel for the Company, such a
representation is required by any of the aforementioned relevant provisions of
law.

              Inability of the Company to obtain authority from any regulatory
body having jurisdiction, which authority is deemed by the Company's counsel to
be necessary to the lawful issuance and sale of any Shares hereunder, shall
relieve the Company of any liability in respect of the failure to issue or sell
such Shares as to which such requisite authority shall not have been obtained.

       14. Reservation of Shares. The Company, during the term of this Plan,
will at all times reserve and keep available such number of Shares as shall be
sufficient to satisfy the requirements of the Plan.

       15. Option Agreement. Options shall be evidenced by written option
agreements in such form as the Board shall approve.

       16. Shareholder Approval. The Plan shall be subject to approval by the
shareholders of the Company within twelve (12) months after the date the Plan is
adopted. Such shareholder approval shall be obtained in the degree and manner
required under applicable state and federal law and any stock exchange rules.


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