<PAGE>
                                                                   EXHIBIT 3.2

                                    BYLAWS


                                      OF


                            FOUNDRY NETWORKS, INC.
<PAGE>

TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                   Page
                                                                                   ----
<S>                                                                                <C>
ARTICLE I - CORPORATE OFFICES...................................................      1

         1.1  Registered Office.................................................      1
         1.2  Other Offices.....................................................      1

ARTICLE II - MEETINGS OF STOCKHOLDERS...........................................      1

         2.1  Place of Meetings.................................................      1
         2.2  Annual Meeting....................................................      1
         2.3  Special Meeting...................................................      2
         2.4  Notice of Stockholder's Meeting; Affidavit of Notice..............      2
         2.5  Advance Notice of Stockholder Nominees............................      3
         2.6  Quorum............................................................      3
         2.7  Adjourned Meeting; Notice.........................................      4
         2.8  Conduct of Business...............................................      4
         2.9  Voting............................................................      4
         2.10 Waiver of Notice..................................................      4
         2.11 Record Date for Stockholder Notice; Voting........................      4
         2.12 Proxies...........................................................      5

ARTICLE III - DIRECTORS.........................................................      5

         3.1  Powers............................................................      5
         3.2  Number of Directors...............................................      5
         3.3  Election, Qualification and Term of Office of Directors...........      5
         3.4  Resignation and Vacancies.........................................      6
         3.5  Place of Meetings; Meetings by Telephone..........................      7
         3.6  Regular Meetings..................................................      7
         3.7  Special Meetings; Notice..........................................      7
         3.8  Quorum............................................................      7
         3.9  Waiver of Notice..................................................      8
         3.10 Board Action by Written Consent without a Meeting.................      8
         3.11 Fees and Compensation of Directors................................      8
         3.12 Approval of Loans to Officers.....................................      8
         3.13 Removal of Directors..............................................      8
         3.14 Chairman of the Board of Directors................................      9

ARTICLE IV - COMMITTEES.........................................................      9

         4.1  Committees of Directors...........................................      9
         4.2  Committee Minutes.................................................      9
         4.3  Meetings and Action of Committees.................................     10

ARTICLE V - OFFICERS............................................................     10

         5.1 Officers...........................................................     10
         5.2 Appointment of Officers............................................     10
         5.3 Subordinate Officers...............................................     10
         5.4 Removal and Resignation of Officers................................     10
</TABLE>

                                       i
<PAGE>

                              TABLE OF CONTENTS
                                  (continued)

<TABLE>
<CAPTION>
                                                                                  Page
                                                                                  ----
<S>                                                                               <C>
         5.5  Vacancies in Offices..............................................    11
         5.6  Chief Executive Officer...........................................    11
         5.7  President.........................................................    11
         5.8  Vice Presidents...................................................    11
         5.9  Secretary.........................................................    11
         5.10 Chief Financial Officer...........................................    12
         5.11 Representation of Shares of Other Corporations....................    12
         5.12 Authority and Duties of Officers..................................    12

ARTICLE VI - INDEMNIFICATION OF DIRECTORS, OFFICERS, EMPLOYEES, AND OTHER AGENTS    12

         6.1  Indemnification of Directors and Officers.........................    12
         6.2  Indemnification of Others.........................................    13
         6.3  Payment of Expenses in Advance....................................    13
         6.4  Indemnity Not Exclusive...........................................    13
         6.5  Insurance.........................................................    13
         6.6  Conflicts.........................................................    14

ARTICLE VII - RECORDS AND REPORTS...............................................    14

         7.1  Maintenance and Inspection of Records.............................    14
         7.2  Inspection by Directors...........................................    14
         7.3  Annual Statement to Stockholders..................................    15

ARTICLE VIII - GENERAL MATTERS..................................................    15

         8.1  Checks............................................................    15
         8.2  Execution of Corporate Contracts and Instruments..................    15
         8.3  Stock Certificates; Partly Paid Shares............................    15
         8.4  Special Designation on Certificates...............................    16
         8.5  Lost Certificates.................................................    16
         8.6  Construction; Definitions.........................................    16
         8.7  Dividends.........................................................    16
         8.8  Fiscal Year.......................................................    16
         8.9  Seal..............................................................    17
         8.10 Transfer of Stock.................................................    17
         8.11 Stock Transfer Agreements.........................................    17
         8.12 Registered Stockholders...........................................    17

ARTICLE IX - AMENDMENTS.........................................................    17
</TABLE>

                                     -ii-
<PAGE>

                                    BYLAWS

                                      OF

                            FOUNDRY NETWORKS, INC.

                                   ARTICLE I

                               CORPORATE OFFICES
                               -----------------

     1.1  Registered Office.
          -----------------

          The registered office of the corporation shall be in the City of
Wilmington, County of New Castle, State of Delaware.  The name of the registered
agent of the corporation at such location is Corporation Service Company.

     1.2  Other Offices.
          -------------

          The Board of Directors may at any time establish other offices at any
place or places where the Corporation is qualified to do business.

                                   ARTICLE II

                            MEETINGS OF STOCKHOLDERS
                            ------------------------

     2.1  Place of Meetings.
          -----------------

          Meetings of stockholders shall be held at any place, within or outside
the State of Delaware, designated by the Board of Directors. In the absence of
any such designation, stockholders' meetings shall be held at the registered
office of the Corporation.

     2.2  Annual Meeting.
          --------------

     (a)  The annual meeting of stockholders shall be held each year on a date
and at a time designated by the Board of Directors.  At the meeting, directors
shall be elected and any other proper business may be transacted.

     (b)  Nominations of persons for election to the Board of Directors of the
Corporation and the proposal of business to be transacted by the stockholders
may be made at an annual meeting of stockholders (i) pursuant to the
Corporation's notice with respect to such meeting, (ii) by or at the direction
of the Board of Directors or (iii) by any stockholder of the Corporation who was
a stockholder of record at the time of giving of the notice provided for in this
Section 2.2, who is entitled to vote at the meeting and who has complied with
the notice procedures set forth in this Section 2.2.

     (c)  In addition to the requirements of Section 2.5, for nominations or
other business to be properly brought before an annual meeting by a stockholder
pursuant to clause (iii) of paragraph (b) of this Section 2.2, the stockholder
must have given timely notice thereof in writing to the secretary of the
Corporation and such business must be a proper matter for stockholder action
under the General Corporation Law of  Delaware.  To be timely, a stockholder's
notice shall be delivered to the secretary at the principal executive offices of
the Corporation not less than 60 days nor more than 90 days prior to the
<PAGE>

first anniversary of the preceding year's annual meeting of stockholders;
provided, however, that in the event that the date of the annual meeting is more
than 30 days prior to or more than 60 days after such anniversary date, notice
by the stockholder to be timely must be so delivered not earlier than the 90th
day prior to such annual meeting and not later than the close of business on the
later of the 60th day prior to such annual meeting or the 10th day following the
day on which public announcement of the date of such meeting is first made. Such
stockholder's notice shall set forth (i) as to each person whom the stockholder
proposes to nominate for election or reelection as a director all information
relating to such person that is required to be disclosed in solicitations of
proxies for election of directors, or is otherwise required, in each case
pursuant to Regulation 14A under the Securities Exchange Act of 1934, as amended
(the "Exchange Act") (including such person's written consent to being named in
the proxy statement as a nominee and to serving as a director if elected); (ii)
as to any other business that the stockholder proposes to bring before the
meeting, a brief description of such business, the reasons for conducting such
business at the meeting and any material interest in such business of such
stockholder and the beneficial owner, if any, on whose behalf the proposal is
made; and (iii) as to the stockholder giving the notice and the beneficial
owner, if any, on whose behalf the nomination or proposal is made (A) the name
and address of such stockholder, as they appear on the Corporation's books, and
of such beneficial owner and (B) the class and number of shares of the
Corporation which are owned beneficially and of record by such stockholder and
such beneficial owner.

     (d) Only such business shall be conducted at an annual meeting of
stockholders as shall have been brought before the meeting in accordance with
the procedures set forth in this Section 2.2.  The chairman of the meeting shall
determine whether a nomination or any business proposed to be transacted by the
stockholders has been properly brought before the meeting and, if any proposed
nomination or business has not been properly brought before the meeting, the
chairman shall declare that such proposed business or nomination shall not be
presented for stockholder action at the meeting.

     (e) For purposes of this Section 2.2, "public announcement" shall mean
disclosure in a press release reported by the Dow Jones News Service, Associated
Press or a comparable national news service.

     (f) Nothing in this Section 2.2 shall be deemed to affect any rights of
stockholders to request inclusion of proposals in the Corporation's proxy
statement pursuant to Rule 14a-8 under the Exchange Act.

     2.3 Special Meeting.
         ----------------

         (a) A special meeting of the stockholders may be called at any time by
the Board of Directors, or by the chairman of the board, or by the president.

         (b) Nominations of persons for election to the Board of Directors may
be made at a special meeting of stockholders at which directors are to be
elected pursuant to such notice of meeting (i) by or at the direction of the
Board of Directors or (ii) by any stockholder of the Corporation who is a
stockholder of record at the time of giving of notice provided for in Section
2.5, who shall be entitled to vote at the meeting and who complies with the
notice procedures set forth in Section 2.5.

     2.4 Notice of Stockholder's Meetings; Affidavit of Notice.
         -----------------------------------------------------

         All notices of meetings of stockholders shall be in writing and shall
be sent or otherwise given in accordance with this Section 2.4 of these Bylaws
not less than 10 nor more than 60 days before

                                      -2-
<PAGE>

the date of the meeting to each stockholder entitled to vote at such meeting (or
such longer or shorter time as is required by Section 2.5 of these Bylaws, if
applicable). The notice shall specify the place, date, and hour of the meeting,
and, in the case of a special meeting, the purpose or purposes for which the
meeting is called.

          Written notice of any meeting of stockholders, if mailed, is given
when deposited in the United States mail, postage prepaid, directed to the
stockholder at his address as it appears on the records of the Corporation.  An
affidavit of the secretary or an assistant secretary or of the transfer agent of
the Corporation that the notice has been given shall, in the absence of fraud,
be prima facie evidence of the facts stated therein.

     2.5  Advance Notice of Stockholder Nominees.
          --------------------------------------

          Only persons who are nominated in accordance with the procedures set
forth in this Section 2.5 shall be eligible for election as directors.
Nominations of persons for election to the Board of Directors of the Corporation
may be made at a meeting of stockholders by or at the direction of the Board of
Directors or by any stockholder of the Corporation entitled to vote for the
election of directors at the meeting who complies with the notice procedures set
forth in this Section 2.5.  Such nominations, other than those made by or at the
direction of the Board of Directors, shall be made pursuant to timely notice in
writing to the secretary of the Corporation.  To be timely, a stockholder's
notice shall be delivered to or mailed and received at the principal executive
offices of the Corporation not less than 60 days nor more than 90 days prior to
the meeting; provided, however, that in the event that less than 60 days' notice
or prior public disclosure of the date of the meeting is given or made to
stockholders, notice by the stockholder to be timely must be so received not
later than the close of business on the 10th day following the day on which such
notice of the date of the meeting was mailed or such public disclosure was made.
Such stockholder's notice shall set forth (a) as to each person whom the
stockholder proposes to nominate for election or re-election as a director, (i)
the name, age, business address and residence address of such person, (ii) the
principal occupation or employment of such person, (iii) the class and number of
shares of the Corporation which are beneficially owned by such person and (iv)
any other information relating to such person that is required to be disclosed
in solicitations of proxies for election of directors, or is otherwise required,
in each case pursuant to Regulation 14A under the Exchange Act (including,
without limitation, such person's written consent to being named in the proxy
statement as a nominee and to serving as a director if elected); and (b) as to
the stockholder giving the notice (i) the name and address, as they appear on
the Corporation's books, of such stockholder and (ii) the class and number of
shares of the Corporation which are beneficially owned by such stockholder.  At
the request of the Board of Directors any person nominated by the Board of
Directors for election as a director shall furnish to the secretary of the
Corporation that information required to be set forth in a stockholder's notice
of nomination which pertains to the nominee.  No person shall be eligible for
election as a director of the Corporation unless nominated in accordance with
the procedures set forth in this Section 2.5.  The chairman of the meeting
shall, if the facts warrant, determine and declare to the meeting that a
nomination was not made in accordance with the procedures prescribed by the
Bylaws, and if he or she should so determine, he or she shall so declare to the
meeting and the defective nomination shall be disregarded.

     2.6  Quorum.
          ------

     The holders of a majority of the stock issued and outstanding and entitled
to vote thereat, present in person or represented by proxy, shall constitute a
quorum at all meetings of the stockholders for the transaction of business
except as otherwise provided by statute or by the Certificate of Incorporation.
If, however, such quorum is not present or represented at any meeting of the
stockholders, then either (a) the

                                      -3-
<PAGE>

chairman of the meeting or (b) the stockholders entitled to vote thereat,
present in person or represented by proxy, shall have power to adjourn the
meeting from time to time, without notice other than announcement at the
meeting, until a quorum is present or represented. At such adjourned meeting at
which a quorum is present or represented, any business may be transacted that
might have been transacted at the meeting as originally noticed.

     2.7   Adjourned Meeting; Notice.
           -------------------------

           When a meeting is adjourned to another time or place, unless these
Bylaws otherwise require, notice need not be given of the adjourned meeting if
the time and place thereof are announced at the meeting at which the adjournment
is taken.  At the adjourned meeting the Corporation may transact any business
that might have been transacted at the original meeting.  If the adjournment is
for more than 30 days, or if after the adjournment a new record date is fixed
for the adjourned meeting, a notice of the adjourned meeting shall be given to
each stockholder of record entitled to vote at the meeting.

     2.8   Conduct of Business.
           -------------------

           The chairman of any meeting of stockholders shall determine the order
of business and the procedure at the meeting, including the manner of voting and
the conduct of business.

     2.9   Voting.
           ------

           (a) The stockholders entitled to vote at any meeting of stockholders
shall be determined in accordance with the provisions of Section 2.11 of these
Bylaws, subject to the provisions of Sections 217 and 218 of the General
Corporation Law of Delaware (relating to voting rights of fiduciaries, pledgors
and joint owners of stock and to voting trusts and other voting agreements).

           (b) Except as may be otherwise provided in the Certificate of
Incorporation, each stockholder shall be entitled to one vote for each share of
capital stock held by such stockholder.

     2.10  Waiver of Notice.
           ----------------

           Whenever notice is required to be given under any provision of the
General Corporation Law of Delaware or of the Certificate of Incorporation or
these Bylaws, a written waiver thereof, signed by the person entitled to notice,
whether before or after the time stated therein, shall be deemed equivalent to
notice.  Attendance of a person at a meeting shall constitute a waiver of notice
of such meeting, except when the person attends a meeting for the express
purpose of objecting, at the beginning of the meeting, to the transaction of any
business because the meeting is not lawfully called or convened.  Neither the
business to be transacted at, nor the purpose of, any regular or special meeting
of the stockholders need be specified in any written waiver of notice unless so
required by the Certificate of Incorporation or these Bylaws.


     2.11  Record Date for Stockholder Notice; Voting.
           ------------------------------------------

           In order that the Corporation may determine the stockholders entitled
to notice of or to vote at any meeting of stockholders or any adjournment
thereof or entitled to receive payment of any dividend or other distribution or
allotment of any rights, or entitled to exercise any rights in respect of any
change, conversion or exchange of stock or for the purpose of any other lawful
action, the Board of

                                      -4-
<PAGE>

Directors may fix, in advance, a record date, which shall not be more than 60
nor less than 10 days before the date of such meeting, nor more than 60 days
prior to any other action. If the Board of Directors does not so fix a record
date:

           (a) The record date for determining stockholders entitled to notice
of or to vote at a meeting of stockholders shall be at the close of business on
the day next preceding the day on which notice is given, or, if notice is
waived, at the close of business on the day next preceding the day on which the
meeting is held.

           (b) The record date for determining stockholders for any other
purpose shall be at the close of business on the day on which the Board of
Directors adopts the resolution relating thereto.

           A determination of stockholders of record entitled to notice of or to
vote at a meeting of stockholders shall apply to any adjournment of the meeting;
provided, however, that the Board of Directors may fix a new record date for the
adjourned meeting.

     2.12  Proxies.
           -------

           Each stockholder entitled to vote at a meeting of stockholders may
authorize another person or persons to act for such stockholder by a written
proxy, signed by the stockholder and filed with the secretary of the
Corporation, but no such proxy shall be voted or acted upon after three years
from its date, unless the proxy provides for a longer period.  A proxy shall be
deemed signed if the stockholder's name is placed on the proxy (whether by
manual signature, typewriting, telegraphic transmission or otherwise) by the
stockholder or the stockholder's attorney-in-fact.  The revocability of a proxy
that states on its face that it is irrevocable shall be governed by the
provisions of Section 212(e) of the General Corporation Law of Delaware.

                                  ARTICLE III

                                   DIRECTORS
                                   ---------

     3.1   Powers.
           ------

           Subject to the provisions of the General Corporation Law of Delaware
and any limitations in the Certificate of Incorporation or these Bylaws relating
to action required to be approved by the stockholders or by the outstanding
shares, the business and affairs of the Corporation shall be managed and all
corporate powers shall be exercised by or under the direction of the Board of
Directors.

     3.2   Number of Directors.
           -------------------

           The number of directors constituting the entire Board of Directors
shall be seven (7). Thereafter, this number may be changed by a resolution of
the Board of Directors or of the stockholders, subject to Section 3.4 of these
Bylaws. No reduction of the authorized number of directors shall have the effect
of removing any director before such director's term of office expires.

     3.3   Election, Qualification and Term of Office of Directors.
           -------------------------------------------------------

           Except as provided in Section 3.4 of these Bylaws, directors shall be
elected at each annual meeting of stockholders to hold office until the next
annual meeting.  Directors need not be

                                      -5-
<PAGE>

stockholders unless so required by the Certificate of Incorporation or these
Bylaws, wherein other qualifications for directors may be prescribed. Each
director, including a director elected to fill a vacancy, shall hold office
until his or her successor is elected and qualified or until his or her earlier
resignation or removal.

           Elections of directors need not be by written ballot.

     3.4   Resignation and Vacancies.
           -------------------------

           Any director may resign at any time upon written notice to the
attention of the secretary of the Corporation.  When one or more directors so
resigns and the resignation is effective at a future date, a majority of the
directors then in office, including those who have so resigned, shall have power
to fill such vacancy or vacancies, the vote thereon to take effect when such
resignation or resignations shall become effective, and each director so chosen
shall hold office as provided in this section in the filling of other vacancies.
A vacancy created by the removal of a director by the vote of the stockholders
or by court order may be filled only by the affirmative vote of a majority of
the shares represented and voting at a duly held meeting at which a quorum is
present (which shares voting affirmatively also constitute a majority of the
quorum).  Each director so elected shall hold office until the next annual
meeting of the stockholders and until a successor has been elected and
qualified.

           Unless otherwise provided in the Certificate of Incorporation or
these Bylaws:

           (a) Vacancies and newly created directorships resulting from any
increase in the authorized number of directors elected by all of the
stockholders having the right to vote as a single class may be filled by a
majority of the directors then in office, although less than a quorum, or by a
sole remaining director.

           (b) Whenever the holders of any class or classes of stock or series
thereof are entitled to elect one or more directors by the provisions of the
Certificate of Incorporation, vacancies and newly created directorships of such
class or classes or series may be filled by a majority of the directors elected
by such class or classes or series thereof then in office, or by a sole
remaining director so elected.

           If at any time, by reason of death or resignation or other cause, the
Corporation should have no directors in office, then any officer or any
stockholder or an executor, administrator, trustee or guardian of a stockholder,
or other fiduciary entrusted with like responsibility for the person or estate
of a stockholder, may call a special meeting of stockholders in accordance with
the provisions of the Certificate of Incorporation or these Bylaws, or may apply
to the Court of Chancery for a decree summarily ordering an election as provided
in Section 211 of the General Corporation Law of Delaware.

           If, at the time of filling any vacancy or any newly created
directorship, the directors then in office constitute less than a majority of
the whole Board of Directors (as constituted immediately prior to any such
increase), then the Court of Chancery may, upon application of any stockholder
or stockholders holding at least 10% of the total number of the shares at the
time outstanding having the right to vote for such directors, summarily order an
election to be held to fill any such vacancies or newly created directorships,
or to replace the directors chosen by the directors then in office as aforesaid,
which election shall be governed by the provisions of Section 211 of the General
Corporation Law of Delaware as far as applicable.

                                      -6-
<PAGE>

     3.5   Place of Meetings; Meetings by Telephone.
           ----------------------------------------

           The Board of Directors of the Corporation may hold meetings, both
regular and special, either within or outside the State of Delaware.

           Unless otherwise restricted by the Certificate of Incorporation or
these Bylaws, members of the Board of Directors, or any committee designated by
the Board of Directors, may participate in a meeting of the Board of Directors,
or any committee, by means of conference telephone or similar communications
equipment by means of which all persons participating in the meeting can hear
each other, and such participation in a meeting shall constitute presence in
person at the meeting.

     3.6   Regular Meetings.
           ----------------

           Regular meetings of the Board of Directors may be held without notice
at such time and at such place as shall from time to time be determined by the
Board of Directors.

     3.7   Special Meetings; Notice.
           ------------------------

           Special meetings of the Board of Directors for any purpose or
purposes may be called at any time by the chairman of the board, the president,
any vice president, the secretary or any two directors.

           Notice of the time and place of special meetings shall be delivered
personally or by telephone to each director or sent by first-class mail or
telegram, charges prepaid, addressed to each director at that director's address
as it is shown on the records of the Corporation.  If the notice is mailed, it
shall be deposited in the United States mail at least four days before the time
of the holding of the meeting.  If the notice is delivered personally or by
telephone or by telegram, it shall be delivered personally or by telephone or to
the telegraph company at least 48 hours before the time of the holding of the
meeting.  Any oral notice given personally or by telephone may be communicated
either to the director or to a person at the office of the director who the
person giving the notice has reason to believe will promptly communicate it to
the director.  The notice need not specify the purpose or the place of the
meeting, if the meeting is to be held at the principal executive office of the
Corporation.

     3.8  Quorum.
          ------

          At all meetings of the Board of Directors, a majority of the
authorized number of directors shall constitute a quorum for the transaction of
business and the act of a majority of the directors present at any meeting at
which there is a quorum shall be the act of the Board of Directors, except as
may be otherwise specifically provided by statute or by the Certificate of
Incorporation.  If a quorum is not present at any meeting of the Board of
Directors, then the directors present thereat may adjourn the meeting from time
to time, without notice other than announcement at the meeting, until a quorum
is present.

          A meeting at which a quorum is initially present may continue to
transact business notwithstanding the withdrawal of directors, if any action
taken is approved by at least a majority of the required quorum for that
meeting.


                                      -7-
<PAGE>

     3.9  Waiver of Notice.
          ----------------

          Whenever notice is required to be given under any provision of the
General Corporation Law of Delaware or of the Certificate of Incorporation or
these Bylaws, a written waiver thereof, signed by the person entitled to notice,
whether before or after the time stated therein, shall be deemed equivalent to
notice.  Attendance of a person at a meeting shall constitute a waiver of notice
of such meeting, except when the person attends a meeting for the express
purpose of objecting, at the beginning of the meeting, to the transaction of any
business because the meeting is not lawfully called or convened.  Neither the
business to be transacted at, nor the purpose of, any regular or special meeting
of the directors, or members of a committee of directors, need be specified in
any written waiver of notice unless so required by the Certificate of
Incorporation or these Bylaws.

     3.10 Board Action by Written Consent without a Meeting.
          -------------------------------------------------

          Unless otherwise restricted by the Certificate of Incorporation or
these Bylaws, any action required or permitted to be taken at any meeting of the
Board of Directors, or of any committee thereof, may be taken without a meeting
if all members of the Board of Directors or committee, as the case may be,
consent thereto in writing and the writing or writings are filed with the
minutes of proceedings of the Board of Directors or committee.  Written consents
representing actions taken by the board or committee may be executed by telex,
telecopy or other facsimile transmission, and such facsimile shall be valid and
binding to the same extent as if it were an original.

     3.11 Fees and Compensation of Directors.
          ----------------------------------

          Unless otherwise restricted by the Certificate of Incorporation or
these Bylaws, the Board of Directors shall have the authority to fix the
compensation of directors.  No such compensation shall preclude any director
from serving the Corporation in any other capacity and receiving compensation
therefor.

     3.12 Approval of Loans to Officers.
          -----------------------------

          The Corporation may lend money to, or guarantee any obligation of, or
otherwise assist any officer or other employee of the Corporation or of its
subsidiary, including any officer or employee who is a director of the
Corporation or its subsidiary, whenever, in the judgment of the directors, such
loan, guaranty or assistance may reasonably be expected to benefit the
Corporation.  The loan, guaranty or other assistance may be with or without
interest and may be unsecured, or secured in such manner as the Board of
Directors shall approve, including, without limitation, a pledge of shares of
stock of the Corporation.  Nothing in this Section 3.2 contained shall be deemed
to deny, limit or restrict the powers of guaranty or warranty of the Corporation
at common law or under any statute.

     3.13 Removal of Directors.
          --------------------

          Unless otherwise restricted by statute, by the Certificate of
Incorporation or by these Bylaws, any director or the entire Board of Directors
may be removed, with or without cause, by the holders of a majority of the
shares then entitled to vote at an election of directors; provided, however,
that if the stockholders of the Corporation are entitled to cumulative voting,
if less than the entire Board of Directors is to be removed, no director may be
removed without cause if the votes cast against his removal would be sufficient
to elect him if then cumulatively voted at an election of the entire Board of
Directors.

                                      -8-
<PAGE>

          No reduction of the authorized number of directors shall have the
effect of removing any director prior to the expiration of such director's term
of office.

     3.14 Chairman of the Board of Directors.
          ----------------------------------

          The Corporation may also have, at the discretion of the Board of
Directors, a chairman of the Board of Directors who shall not be considered an
officer of the Corporation.

                                  ARTICLE IV

                                  COMMITTEES
                                  ----------

     4.1  Committees of Directors.
          -----------------------

          The Board of Directors may, by resolution passed by a majority of the
whole Board of Directors, designate one or more committees, with each committee
to consist of one or more of the directors of the Corporation.  The Board of
Directors may designate one or more directors as alternate members of any
committee, who may replace any absent or disqualified member at any meeting of
the committee.  In the absence or disqualification of a member of a committee,
the member or members thereof present at any meeting and not disqualified from
voting, whether or not such member or members constitute a quorum, may
unanimously appoint another member of the Board of Directors to act at the
meeting in the place of any such absent or disqualified member.  Any such
committee, to the extent provided in the resolution of the Board of Directors or
in the Bylaws of the Corporation, shall have and may exercise all the powers and
authority of the Board of Directors in the management of the business and
affairs of the Corporation, and may authorize the seal of the Corporation to be
affixed to all papers that may require it; but no such committee shall have the
power or authority to (a) amend the Certificate of Incorporation (except that a
committee may, to the extent authorized in the resolution or resolutions
providing for the issuance of shares of stock adopted by the Board of Directors
as provided in Section 151(a) of the General Corporation Law of Delaware, fix
the designations and any of the preferences or rights of such shares relating to
dividends, redemption, dissolution, any distribution of assets of the
Corporation or the conversion into, or the exchange of such shares for, shares
of any other class or classes or any other series of the same or any other class
or classes of stock of the Corporation or fix the number of shares of any series
of stock or authorize the increase or decrease of the shares of any series), (b)
adopt an agreement of merger or consolidation under Sections 251 or 252 of the
General Corporation Law of Delaware, (c) recommend to the stockholders the sale,
lease or exchange of all or substantially all of the Corporation's property and
assets, (d) recommend to the stockholders a dissolution of the Corporation or a
revocation of a dissolution, or (e) amend the Bylaws of the Corporation; and,
unless the board resolution establishing the committee, the Bylaws or the
Certificate of Incorporation expressly so provide, no such committee shall have
the power or authority to declare a dividend, to authorize the issuance of
stock, or to adopt a certificate of ownership and merger pursuant to Section 253
of the General Corporation Law of Delaware.

     4.2  Committee Minutes.
          -----------------

          Each committee shall keep regular minutes of its meetings and report
the same to the Board of Directors when required.

                                      -9-
<PAGE>

     4.3  Meetings and Action of Committees.
          ---------------------------------

          Meetings and actions of committees shall be governed by, and held and
taken in accordance with, the provisions of Section 3.5 (place of meetings and
meetings by telephone), Section 3.6 (regular meetings), Section 3.7 (special
meetings and notice), Section 3.8 (quorum), Section 3.9 (waiver of notice), and
Section 3.10 (action without a meeting) of these Bylaws, with such changes in
the context of such provisions as are necessary to substitute the committee and
its members for the Board of Directors and its members; provided, however, that
the time of regular meetings of committees may be determined either by
resolution of the Board of Directors or by resolution of the committee, that
special meetings of committees may also be called by resolution of the Board of
Directors and that notice of special meetings of committees shall also be given
to all alternate members, who shall have the right to attend all meetings of the
committee.  The Board of Directors may adopt rules for the government of any
committee not inconsistent with the provisions of these Bylaws.

                                   ARTICLE V

                                    OFFICERS
                                    --------

     5.1  Officers.
          --------

          The officers of the Corporation shall be a chief executive officer, a
president, a secretary, and a chief financial officer.  The Corporation may also
have, at the discretion of the Board of Directors, one or more vice presidents,
one or more assistant secretaries, one or more assistant treasurers, and any
such other officers as may be appointed in accordance with the provisions of
Section 5.3 of these Bylaws.  Any number of offices may be held by the same
person.

     5.2  Appointment of Officers.
          -----------------------

          The officers of the Corporation, except such officers as may be
appointed in accordance with the provisions of Sections 5.3 or 5.5 of these
Bylaws, shall be appointed by the Board of Directors, subject to the rights, if
any, of an officer under any contract of employment.

     5.3  Subordinate Officers.
          --------------------

          The Board of Directors may appoint, or empower the chief executive
officer or the president to appoint, such other officers and agents as the
business of the Corporation may require, each of whom shall hold office for such
period, have such authority, and perform such duties as are provided in these
Bylaws or as the Board of Directors may from time to time determine.

     5.4  Removal and Resignation of Officers.
          -----------------------------------

          Subject to the rights, if any, of an officer under any contract of
employment, any officer may be removed, either with or without cause, by an
affirmative vote of the majority of the Board of Directors at any regular or
special meeting of the Board of Directors or, except in the case of an officer
chosen by the Board of Directors, by any officer upon whom such power of removal
may be conferred by the Board of Directors.

          Any officer may resign at any time by giving written notice to the
attention of the secretary of the Corporation.  Any resignation shall take
effect at the date of the receipt of that notice or at any later time specified
in that notice; and, unless otherwise specified in that notice, the acceptance
of

                                      -10-
<PAGE>

the resignation shall not be necessary to make it effective. Any resignation is
without prejudice to the rights, if any, of the Corporation under any contract
to which the officer is a party.

     5.5  Vacancies in Offices.
          --------------------

          Any vacancy occurring in any office of the Corporation shall be filled
by the Board of Directors.

     5.6  Chief Executive Officer.
          -----------------------

          Subject to such supervisory powers, if any, as may be given by the
Board of Directors to the chairman of the board, if any, the chief executive
officer of the Corporation shall, subject to the control of the Board of
Directors, have general supervision, direction, and control of the business and
the officers of the Corporation.  He or she shall preside at all meetings of the
stockholders and, in the absence or nonexistence of a chairman of the board, at
all meetings of the Board of Directors and shall have the general powers and
duties of management usually vested in the office of chief executive officer of
a corporation and shall have such other powers and duties as may be prescribed
by the Board of Directors or these Bylaws.

     5.7  President.
          ---------

          Subject to such supervisory powers, if any, as may be given by the
Board of Directors to the chairman of the board (if any) or the chief executive
officer, the president shall have general supervision, direction, and control of
the business and other officers of the Corporation.  He or she shall have the
general powers and duties of management usually vested in the office of
president of a corporation and such other powers and duties as may be prescribed
by the Board of Directors or these Bylaws.

     5.8  Vice Presidents.
          ---------------

          In the absence or disability of the chief executive officer and
president, the vice presidents, if any, in order of their rank as fixed by the
Board of Directors or, if not ranked, a vice president designated by the Board
of Directors, shall perform all the duties of the president and when so acting
shall have all the powers of, and be subject to all the restrictions upon, the
president.  The vice presidents shall have such other powers and perform such
other duties as from time to time may be prescribed for them respectively by the
Board of Directors, these Bylaws, the president or the chairman of the board.

     5.9  Secretary.
          ---------

          The secretary shall keep or cause to be kept, at the principal
executive office of the Corporation or such other place as the Board of
Directors may direct, a book of minutes of all meetings and actions of
directors, committees of directors, and stockholders.  The minutes shall show
the time and place of each meeting, the names of those present at directors'
meetings or committee meetings, the number of shares present or represented at
stockholders' meetings, and the proceedings thereof.

          The secretary shall keep, or cause to be kept, at the principal
executive office of the Corporation or at the office of the Corporation's
transfer agent or registrar, as determined by resolution of the Board of
Directors, a share register, or a duplicate share register, showing the names of
all stockholders and their addresses, the number and classes of shares held by
each, the number and date of

                                      -11-
<PAGE>

certificates evidencing such shares, and the number and date of cancellation of
every certificate surrendered for cancellation.

          The secretary shall give, or cause to be given, notice of all meetings
of the stockholders and of the Board of Directors required to be given by law or
by these Bylaws.  He or she shall keep the seal of the Corporation, if one be
adopted, in safe custody and shall have such other powers and perform such other
duties as may be prescribed by the Board of Directors or by these Bylaws.

     5.10 Chief Financial Officer.
          -----------------------

          The chief financial officer shall keep and maintain, or cause to be
kept and maintained, adequate and correct books and records of accounts of the
properties and business transactions of the Corporation, including accounts of
its assets, liabilities, receipts, disbursements, gains, losses, capital
retained earnings, and shares. The books of account shall at all reasonable
times be open to inspection by any director.

          The chief financial officer shall deposit all moneys and other
valuables in the name and to the credit of the Corporation with such
depositories as may be designated by the Board of Directors. He or she shall
disburse the funds of the Corporation as may be ordered by the Board of
Directors, shall render to the president, the chief executive officer, or the
directors, upon request, an account of all his or her transactions as chief
financial officer and of the financial condition of the Corporation, and shall
have other powers and perform such other duties as may be prescribed by the
Board of Directors or the Bylaws.

     5.11 Representation of Shares of Other Corporations.
          ----------------------------------------------

          The chairman of the board, the chief executive officer, the president,
any vice president, the chief financial officer, the secretary or assistant
secretary of this Corporation, or any other person authorized by the Board of
Directors or the chief executive officer or the president or a vice president,
is authorized to vote, represent, and exercise on behalf of this Corporation all
rights incident to any and all shares of any other corporation or corporations
standing in the name of this Corporation.  The authority granted herein may be
exercised either by such person directly or by any other person authorized to do
so by proxy or power of attorney duly executed by the person having such
authority.

     5.12 Authority and Duties of Officers.
          --------------------------------

          In addition to the foregoing authority and duties, all officers of the
Corporation shall respectively have such authority and perform such duties in
the management of the business of the Corporation as may be designated from time
to time by the Board of Directors or the stockholders.

                                   ARTICLE VI

      INDEMNIFICATION OF DIRECTORS, OFFICERS, EMPLOYEES, AND OTHER AGENTS
      -------------------------------------------------------------------

     6.1  Indemnification of Directors and Officers.
          -----------------------------------------

          The Corporation shall, to the maximum extent and in the manner
permitted by the General Corporation Law of Delaware, indemnify each of its
directors and officers against expenses (including attorneys' fees), judgments,
fines, settlements and other amounts actually and reasonably incurred in
connection with any proceeding, arising by reason of the fact that such person
is or was an

                                      -12-
<PAGE>

agent of the Corporation. For purposes of this Section 6.1, a "director" or
"officer" of the Corporation includes any person (a) who is or was a director or
officer of the Corporation, (b) who is or was serving at the request of the
Corporation as a director or officer of another corporation, partnership, joint
venture, trust or other enterprise, or (c) who was a director or officer of a
Corporation which was a predecessor corporation of the Corporation or of another
enterprise at the request of such predecessor corporation.

     6.2  Indemnification of Others.
          -------------------------

          The Corporation shall have the power, to the maximum extent and in the
manner permitted by the General Corporation Law of Delaware, to indemnify each
of its employees and agents (other than directors and officers) against expenses
(including attorneys' fees), judgments, fines, settlements and other amounts
actually and reasonably incurred in connection with any proceeding, arising by
reason of the fact that such person is or was an agent of the Corporation.  For
purposes of this Section 6.2, an "employee" or "agent" of the Corporation (other
than a director or officer) includes any person (a) who is or was an employee or
agent of the Corporation, (b) who is or was serving at the request of the
Corporation as an employee or agent of another corporation, partnership, joint
venture, trust or other enterprise, or (c) who was an employee or agent of a
corporation which was a predecessor corporation of the Corporation or of another
enterprise at the request of such predecessor corporation.

     6.3  Payment of Expenses in Advance.
          ------------------------------

          Expenses incurred in defending any action or proceeding for which
indemnification is required pursuant to Section 6.1 or for which indemnification
is permitted pursuant to Section 6.2 following authorization thereof by the
Board of Directors shall be paid by the Corporation in advance of the final
disposition of such action or proceeding upon receipt of an undertaking by or on
behalf of the indemnified party to repay such amount if it shall ultimately be
determined that the indemnified party is not entitled to be indemnified as
authorized in this Article VI.

     6.4  Indemnity Not Exclusive.
          -----------------------

          The indemnification provided by this Article VI shall not be deemed
exclusive of any other rights to which those seeking indemnification may be
entitled under any Bylaw, agreement, vote of shareholders or disinterested
directors or otherwise, both as to action in an official capacity and as to
action in another capacity while holding such office, to the extent that such
additional rights to indemnification are authorized in the Certificate of
Incorporation

     6.5  Insurance.
          ---------

          The Corporation may purchase and maintain insurance on behalf of any
person who is or was a director, officer, employee or agent of the Corporation,
or is or was serving at the request of the Corporation as a director, officer,
employee or agent of another corporation, partnership, joint venture, trust or
other enterprise against any liability asserted against him or her and incurred
by him or her in any such capacity, or arising out of his or her status as such,
whether or not the Corporation would have the power to indemnify him or her
against such liability under the provisions of the General Corporation Law of
Delaware.

                                      -13-
<PAGE>

     6.6  Conflicts.
          ---------

          No indemnification or advance shall be made under this Article VI,
except where such indemnification or advance is mandated by law or the order,
judgment or decree of any court of competent jurisdiction, in any circumstance
where it appears:

          (a) That it would be inconsistent with a provision of the Certificate
of Incorporation, these Bylaws, a resolution of the stockholders or an agreement
in effect at the time of the accrual of the alleged cause of the action asserted
in the proceeding in which the expenses were incurred or other amounts were
paid, which prohibits or otherwise limits indemnification; or

          (b) That it would be inconsistent with any condition expressly imposed
by a court in approving a settlement.

                                  ARTICLE VII

                              RECORDS AND REPORTS
                              -------------------

     7.1  Maintenance and Inspection of Records.
          -------------------------------------

          The Corporation shall, either at its principal executive offices or at
such place or places as designated by the Board of Directors, keep a record of
its stockholders listing their names and addresses and the number and class of
shares held by each stockholder, a copy of these Bylaws as amended to date,
accounting books, and other records.

          Any stockholder of record, in person or by attorney or other agent,
shall, upon written demand under oath stating the purpose thereof, have the
right during the usual hours for business to inspect for any proper purpose the
Corporation's stock ledger, a list of its stockholders, and its other books and
records and to make copies or extracts therefrom.  A proper purpose shall mean a
purpose reasonably related to such person's interest as a stockholder.  In every
instance where an attorney or other agent is the person who seeks the right to
inspection, the demand under oath shall be accompanied by a power of attorney or
such other writing that authorizes the attorney or other agent to so act on
behalf of the stockholder.  The demand under oath shall be directed to the
Corporation at its registered office in Delaware or at its principal place of
business.

     7.2  Inspection by Directors.
          -----------------------

          Any director shall have the right to examine the Corporation's stock
ledger, a list of its stockholders, and its other books and records for a
purpose reasonably related to his or her position as a director.  The Court of
Chancery is hereby vested with the exclusive jurisdiction to determine whether a
director is entitled to the inspection sought.  The Court may summarily order
the Corporation to permit the director to inspect any and all books and records,
the stock ledger, and the stock list and to make copies or extracts therefrom.
The Court may, in its discretion, prescribe any limitations or conditions with
reference to the inspection, or award such other and further relief as the Court
may deem just and proper.

                                      -14-
<PAGE>

     7.3  Annual Statement to Stockholders.
          --------------------------------

          The Board of Directors shall present at each annual meeting, and at
any special meeting of the stockholders when called for by vote of the
stockholders, a full and clear statement of the business and condition of the
Corporation.

                                  ARTICLE VIII

                                GENERAL MATTERS
                                ---------------

     8.1  Checks.
          ------

          From time to time, the Board of Directors shall determine by
resolution which person or persons may sign or endorse all checks, drafts, other
orders for payment of money, notes or other evidences of indebtedness that are
issued in the name of or payable to the Corporation, and only the persons so
authorized shall sign or endorse those instruments.

     8.2  Execution of Corporate Contracts and Instruments.
          ------------------------------------------------

          The Board of Directors, except as otherwise provided in these Bylaws,
may authorize any officer or officers, or agent or agents, to enter into any
contract or execute any instrument in the name of and on behalf of the
Corporation; such authority may be general or confined to specific instances.
Unless so authorized or ratified by the Board of Directors or within the agency
power of an officer, no officer, agent or employee shall have any power or
authority to bind the Corporation by any contract or engagement or to pledge its
credit or to render it liable for any purpose or for any amount.

     8.3  Stock Certificates; Partly Paid Shares.
          --------------------------------------

          The shares of the Corporation shall be represented by certificates,
provided that the Board of Directors of the Corporation may provide by
resolution or resolutions that some or all of any or all classes or series of
its stock shall be uncertificated shares.  Any such resolution shall not apply
to shares represented by a certificate until such certificate is surrendered to
the Corporation.  Notwithstanding the adoption of such a resolution by the Board
of Directors, every holder of stock represented by certificates and upon request
every holder of uncertificated shares shall be entitled to have a certificate
signed by, or in the name of the Corporation by the chairman or vice-chairman of
the Board of Directors, or the chief executive officer or the president or vice-
president, and by the chief financial officer or an assistant treasurer, or the
secretary or an assistant secretary of the Corporation representing the number
of shares registered in certificate form.  Any or all of the signatures on the
certificate may be a facsimile.  In case any officer, transfer agent or
registrar who has signed or whose facsimile signature has been placed upon a
certificate has ceased to be such officer, transfer agent or registrar before
such certificate is issued, it may be issued by the Corporation with the same
effect as if he or she were such officer, transfer agent or registrar at the
date of issue.

          The Corporation may issue the whole or any part of its shares as
partly paid and subject to call for the remainder of the consideration to be
paid therefor.  Upon the face or back of each stock certificate issued to
represent any such partly paid shares, upon the books and records of the
Corporation in the case of uncertificated partly paid shares, the total amount
of the consideration to be paid therefor and the amount paid thereon shall be
stated.  Upon the declaration of any dividend on fully paid shares, the
Corporation shall declare a dividend upon partly paid shares of the same class,
but only upon the basis of the percentage of the consideration actually paid
thereon.

                                      -15-
<PAGE>

     8.4  Special Designation on Certificates.
          -----------------------------------

          If the Corporation is authorized to issue more than one class of stock
or more than one series of any class, then the powers, the designations, the
preferences, and the relative, participating, optional or other special rights
of each class of stock or series thereof and the qualifications, limitations or
restrictions of such preferences and/or rights shall be set forth in full or
summarized on the face or back of the certificate that the Corporation shall
issue to represent such class or series of stock; provided, however, that,
except as otherwise provided in Section 202 of the General Corporation Law of
Delaware, in lieu of the foregoing requirements there may be set forth on the
face or back of the certificate that the Corporation shall issue to represent
such class or series of stock a statement that the Corporation will furnish
without charge to each stockholder who so requests the powers, the designations,
the preferences, and the relative, participating, optional or other special
rights of each class of stock or series thereof and the qualifications,
limitations or restrictions of such preferences and/or rights.

     8.5  Lost Certificates.
          -----------------

          Except as provided in this Section 8.5, no new certificates for shares
shall be issued to replace a previously issued certificate unless the latter is
surrendered to the Corporation and canceled at the same time.  The Corporation
may issue a new certificate of stock or uncertificated shares in the place of
any certificate previously issued by it, alleged to have been lost, stolen or
destroyed, and the Corporation may require the owner of the lost, stolen or
destroyed certificate, or the owner's legal representative, to give the
Corporation a bond sufficient to indemnify it against any claim that may be made
against it on account of the alleged loss, theft or destruction of any such
certificate or the issuance of such new certificate or uncertificated shares.

     8.6  Construction; Definitions.
          -------------------------

          Unless the context requires otherwise, the general provisions, rules
of construction, and definitions in the Delaware General Corporation Law shall
govern the construction of these Bylaws.  Without limiting the generality of
this provision, the singular number includes the plural, the plural number
includes the singular, and the term "person" includes both a corporation and a
natural person.

     8.7  Dividends.
          ---------

          The directors of the Corporation, subject to any restrictions
contained in (a) the General Corporation Law of Delaware or (b) the Certificate
of Incorporation, may declare and pay dividends upon the shares of its capital
stock.  Dividends may be paid in cash, in property, or in shares of the
Corporation's capital stock.

          The directors of the Corporation may set apart out of any of the funds
of the Corporation available for dividends a reserve or reserves for any proper
purpose and may abolish any such reserve. Such purposes shall include but not be
limited to equalizing dividends, repairing or maintaining any property of the
Corporation, and meeting contingencies.

     8.8  Fiscal Year.
          -----------

          The fiscal year of the Corporation shall be fixed by resolution of the
Board of Directors and may be changed by the Board of Directors.

                                      -16-
<PAGE>

     8.9  Seal.
          ----

          The Corporation may adopt a corporate seal, which may be altered at
pleasure, and may use the same by causing it or a facsimile thereof, to be
impressed or affixed or in any other manner reproduced.

     8.10 Transfer of Stock.
          -----------------

          Upon surrender to the Corporation or the transfer agent of the
Corporation of a certificate for shares duly endorsed or accompanied by proper
evidence of succession, assignation or authority to transfer, it shall be the
duty of the Corporation to issue a new certificate to the person entitled
thereto, cancel the old certificate, and record the transaction in its books.

     8.11 Stock Transfer Agreements.
          -------------------------

          The Corporation shall have power to enter into and perform any
agreement with any number of stockholders of any one or more classes of stock of
the Corporation to restrict the transfer of shares of stock of the Corporation
of any one or more classes owned by such stockholders in any manner not
prohibited by the General Corporation Law of Delaware.

     8.12 Registered Stockholders.
          -----------------------

          The Corporation shall be entitled to recognize the exclusive right of
a person registered on its books as the owner of shares to receive dividends and
to vote as such owner, shall be entitled to hold liable for calls and
assessments the person registered on its books as the owner of shares, and shall
not be bound to recognize any equitable or other claim to or interest in such
share or shares on the part of another person, whether or not it shall have
express or other notice thereof, except as otherwise provided by the laws of
Delaware.

                                   ARTICLE IX

                                   AMENDMENTS
                                   ----------

          The Bylaws of the Corporation may be adopted, amended or repealed by
the stockholders entitled to vote; provided, however, that the Corporation may,
in its Certificate of Incorporation, confer the power to adopt, amend or repeal
Bylaws upon the directors.  The fact that such power has been so conferred upon
the directors shall not divest the stockholders of the power, nor limit their
power to adopt, amend or repeal Bylaws.

                                      -17-
<PAGE>

                  CERTIFICATE OF ADOPTION BY THE SECRETARY OF
                            FOUNDRY NETWORKS, INC.

     The undersigned, Joshua L. Green, hereby certifies that he is the duly
elected and acting Secretary of Foundry Networks, Inc., a Delaware corporation
(the "Corporation"), and that the Bylaws attached hereto constitute the Bylaws
of said Corporation in effect as of the date hereof.

     IN WITNESS WHEREOF, the undersigned has hereunto subscribed his name this
1st day of October, 1999.



                                        ________________________________________
                                        Joshua L. Green, Secretary