<PAGE>   1
      AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON SEPTEMBER 25, 1998

                                                         Registration No. 333-

===============================================================================
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                   ----------

                                    FORM S-8

                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933
                                   ----------

                               FORE SYSTEMS, INC.
             (Exact Name of Registrant as Specified in Its Charter)

          DELAWARE                                      25-1628117
(State or Other Jurisdiction of             (I.R.S. Employer Identification No.)
 Incorporation or Organization)

           1000 FORE DRIVE
       WARRENDALE, PENNSYLVANIA                                     15086-7502
(Address of Principal Executive Offices)                            (Zip Code)



              BERKELEY NETWORKS, INC. SUBSTITUTE STOCK OPTION PLAN
                            (Full Title of the Plan)

                                 THOMAS J. GILL
                      PRESIDENT AND CHIEF EXECUTIVE OFFICER
                               FORE SYSTEMS, INC.
                                 1000 FORE DRIVE
                       WARRENDALE, PENNSYLVANIA 15086-7502
                     (Name and Address of Agent for Service)

                                 (724) 742-4444
          (Telephone Number, Including Area Code, of Agent for Service)

                         Copy of all communications to:
                             CHRISTOPHER H. GEBHARDT
                 VICE PRESIDENT, CORPORATE COUNSEL AND SECRETARY
                               FORE SYSTEMS, INC.
                                 1000 FORE DRIVE
                       WARRENDALE, PENNSYLVANIA 15086-7502
                                 (724) 742-7658

                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>

====================================================================================================================================

                                                                  PROPOSED MAXIMUM        PROPOSED MAXIMUM           AMOUNT OF
                                              AMOUNT TO BE       OFFERING PRICE PER      AGGREGATE OFFERING        REGISTRATION
 TITLE OF SECURITIES TO BE REGISTERED          REGISTERED             SHARE(1)                PRICE(1)                FEE(1)
------------------------------------------------------------------------------------------------------------------------------------
<S>                                          <C>                      <C>                    <C>                    <C>      
COMMON STOCK, PAR VALUE $.01 PER SHARE
BERKELEY NETWORKS, INC. SUBSTITUTE STOCK     618,999 shares           $20.0315               $12,399,479              $3,658   
OPTION PLAN
====================================================================================================================================

</TABLE>

(1)  Estimated solely for the purpose of calculating the registration fee;
     computed in accordance with Rule 457(h) on the basis of the average of the
     high and low sales prices for the Common Stock on September 18, 1998 as
     reported on The Nasdaq National Market.
===============================================================================



<PAGE>   2



                                     PART II


               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT


ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.

         The following documents filed by FORE Systems, Inc. (the "Company")
with the Securities and Exchange Commission (the "Commission") are incorporated
by reference into this Registration Statement on Form S-8 (the "Registration
Statement"):

         1.       The Company's Annual Report on Form 10-K for the fiscal year
                  ended March 31, 1998;

         2.       The Company's Quarterly Report on Form 10-Q for the fiscal
                  quarter ended June 30, 1998;

         3.       The Company's Current Report on Form 8-K dated September 11,
                  1998;

         4.       The Company's Current Report on Form 8-K/A dated September 11,
                  1998; and

         5.       The description of the Company's Common Stock, par value $.01
                  per share ("Common Stock"), contained in the Company's
                  Registration Statement on Form 8-A under the Securities
                  Exchange Act of 1934 (the "Exchange Act"), including any
                  amendment or report filed for the purpose of updating such
                  description.

         All documents subsequently filed by the Company with the Commission
pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act after the
date of this Registration Statement, but prior to the filing of a post-effective
amendment to this Registration Statement which indicates that all securities
offered by this Registration Statement have been sold or which deregisters all
such securities then remaining unsold, shall be deemed to be incorporated by
reference into this Registration Statement. Each document incorporated by
reference into this Registration Statement shall be deemed to be a part of this
Registration Statement from the date of the filing of such document with the
Commission until the information contained therein is superseded or updated by
any subsequently filed document which is incorporated by reference into this
Registration Statement or by any document which constitutes part of the
prospectus relating to the Berkeley Networks, Inc. Substitute Stock Option Plan
meeting the requirements of Section 10(a) of the Securities Act of 1933, as
amended (the "Securities Act").

ITEM 4.  DESCRIPTION OF SECURITIES.

         The class of securities to be offered under this Registration Statement
is registered under Section 12(g) of the Exchange Act.

ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.

         The validity of the shares of Common Stock to be issued under this
Registration Statement will be passed upon for the Company by Morgan, Lewis &
Bockius LLP, Pittsburgh, Pennsylvania. As of September 25, 1998, Marlee S.
Myers, a partner of Morgan, Lewis & Bockius LLP, held options to acquire up to
40,000 shares of Common Stock.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.

         Section 102(b)(7) of the Delaware General Corporation Law (the "DGCL")
permits a corporation, in its certificate of incorporation, to limit or
eliminate, subject to certain statutory limitations, the liability of directors
to the corporation or its stockholders for monetary damages for breaches of
fiduciary duty, except for liability (a) for any breach of the director's duty
of loyalty to the corporation or its stockholders, (b) for acts or omissions not
in good faith or which involve intentional misconduct or a knowing violation of
law, (c) under Section 174 of the DGCL or (d) for any transaction from which the
director derived an improper personal benefit. Article Eighth of the Company's
Amended and Restated Certificate of Incorporation, as amended, provides that the
personal liability of directors of the Company is eliminated to the fullest
extent permitted by Section 102(b)(7) of the DGCL.


                                      II-1
<PAGE>   3


         Under Section 145 of the DGCL, a corporation has the power to indemnify
directors and officers under certain prescribed circumstances and subject to
certain limitations against certain costs and expenses, including attorneys'
fees actually and reasonably incurred in connection with any action, suit or
proceeding, whether civil, criminal, administrative or investigative, to which
any of them is a party by reason of his being a director or officer of the
corporation if it is determined that he acted in accordance with the applicable
standard of conduct set forth in such statutory provision. Article V of the
Company's Second Amended and Restated By-Laws provides that the Company will
indemnify any person who was or is a party or is threatened to be made a party
to any threatened, pending or completed action, suit or proceeding by reason of
the fact that he is or was a director, officer, employee or agent of the
Company, or is or was serving at the request of the Company as a director,
officer, employee or agent of another entity, against certain liabilities, costs
and expenses. Article V further permits the Company to maintain insurance on
behalf of any person who is or was a director, officer, employee or agent of the
Company, or is or was serving at the request of the Company as a director,
officer, employee or agent of another entity against any liability asserted
against such person and incurred by such person in any such capacity or arising
out of his status as such, whether or not the Company would have the power to
indemnify such person against such liability under the DGCL. The Company
maintains directors' and officers' liability insurance.

ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED.

         Not Applicable.

ITEM 8.  EXHIBITS.

         The following exhibits are filed herewith or incorporated by reference
as part of this Registration Statement:

<TABLE>
<CAPTION>

 EXHIBIT NO.                                           DESCRIPTION
------------         ---------------------------------------------------------------------------------
     <S>            <C>                                                                             
     4.1             Amended and Restated  Certificate  of  Incorporation  of FORE Systems,  Inc. (as
                     amended  by  Certificate  of  Amendment  dated  May 6,  1996)  (incorporated  by
                     reference to Exhibit 3.1 to the Company's Annual Report on
                     Form 10-K for the fiscal year ended March 31, 1996).

     4.2             Second Amended and Restated By-Laws of FORE Systems, Inc.
                     (as amended through March 5, 1997) (incorporated by
                     reference to Exhibit 3.2 to the Company's Annual Report on
                     Form 10-K for the fiscal year ended March 31, 1997).

     5.1             Opinion of Morgan,  Lewis & Bockius  LLP as to the  legality  of the  securities
                     being registered (filed herewith).

    23.1             Consent of Morgan,  Lewis & Bockius LLP  (included  in opinion  filed as Exhibit
                     5.1).

    23.2             Consent of PricewaterhouseCoopers LLP (filed herewith).

    23.3             Consent of PricewaterhouseCoopers LLP (filed herewith).

    24.1             Power  of  Attorney  (set  forth  on the  signature  page of  this  Registration
                     Statement).

    99.1             Berkeley Networks, Inc. Substitute Stock Option Plan (filed herewith).

</TABLE>

ITEM 9.  UNDERTAKINGS.

         (1) The undersigned registrant hereby undertakes: (i) to file, during
any period in which offers or sales are being made, a post-effective amendment
to this Registration Statement to include any material information with respect
to the plan of distribution not previously disclosed in the Registration
Statement or any material change to such information in the Registration
Statement; (ii) that, for the purpose of determining any liability under the
Securities Act, each such post-effective amendment shall be deemed to be a new
registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof; and (iii) to remove from registration by means of a
post-effective amendment any of the securities being registered which remain
unsold at the termination of the offering.


                                      II-2
<PAGE>   4


         (2) The undersigned registrant hereby undertakes that for purposes of
determining any liability under the Securities Act, each filing of the
registrant's annual report pursuant to section 13(a) or section 15(d) of the
Exchange Act that is incorporated by reference in the Registration Statement
shall be deemed to be a new registration statement relating to the securities
offered therein, and the offering of such securities at that time shall be
deemed to be the initial bona fide offering thereof.

         (3) Insofar as indemnification for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of the registrant pursuant to the foregoing provisions, or otherwise, the
registrant has been advised that in the opinion of the Commission such
indemnification is against public policy as expressed in the Securities Act and
is, therefore, unenforceable. In the event that a claim for indemnification
against such liability (other than the payment by the registrant of expenses
incurred or paid by a director, officer or controlling person of the registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Securities Act and will be governed by the final
adjudication of such issue.


                                      II-3
<PAGE>   5



                                   SIGNATURES

         Pursuant to the requirements of the Securities Act, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the Borough of Warrendale, Commonwealth of Pennsylvania on
September 25, 1998.

                                          FORE Systems, Inc.


                                      By: /s/ THOMAS J. GILL
                                          -------------------------------------
                                          Thomas J. Gill
                                          President and Chief Executive Officer

         KNOW ALL MEN BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Eric C. Cooper and Thomas J. Gill, and
each of them, his true and lawful attorneys-in-fact and agents, with full power
of substitution and resubstitution, for him and in his name, place and stead, in
any and all capacities, to sign any and all amendments to this Registration
Statement, and to file the same, with all exhibits thereto, and other
documentation in connection therewith, with the Commission, granting unto said
attorneys-in-fact and agents full power and authority to do and perform each and
every act and thing requisite and necessary to be done in and about the
premises, as fully to all intents and purposes as he might or could do in
person, hereby ratifying and confirming all that said attorneys-in-fact and
agents, or their substitute or substitutes, may lawfully do or cause to be done
by virtue hereof.

         Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed by the following persons in the capacities and on the
dates indicated.

<TABLE>
<CAPTION>

              Signature                                    Title                                     Date
              ---------                                    -----                                     ----

<S>                                   <C>                                                   <C> 
  /s/ ERIC C. COOPER                   Chairman and a Director                                September 25, 1998
  ------------------------------
  Eric C. Cooper

  /s/ THOMAS J. GILL                   President and Chief Executive Officer (Principal       September 25, 1998
  ------------------------------       Executive Officer) and a Director
  Thomas J. Gill                                                          

  /s/ ROBERT D. SANSOM                 Senior Vice President and Chief Technical              September 25, 1998
  ------------------------------       Officer and a Director
  Robert D. Sansom                                              

  /s/ BRUCE E. HANEY                   Senior Vice President and Chief Financial              September 25, 1998
  ------------------------------       Officer (Principal Financial Officer)
  Bruce E. Haney                                                              

  /s/ GARY J. BRUNNER                  Vice President, Controller and Treasurer               September 25, 1998
  ------------------------------       (Principal Accounting Officer)
  Gary J. Brunner                                                      

  /s/ JOHN C. BAKER                    Director                                               September 25, 1998
  ------------------------------
  John C. Baker

                                       Director                                               September 25, 1998
  ------------------------------
  Daniel W. McGlaughlin

                                       Director                                               September 25, 1998
  ------------------------------
  Daniel R. Hesse

  /s/ JOHN T. LAMACCHIA                Director                                               September 25, 1998
  ------------------------------
  John T. LaMacchia
</TABLE>


<PAGE>   6



                                  EXHIBIT INDEX


 EXHIBIT NO.                          DESCRIPTION
 -----------         -----------------------------------------------------
      5.1            Opinion of Morgan, Lewis & Bockius LLP.

     23.2            Consent of PricewaterhouseCoopers LLP.

     23.3            Consent of PricewaterhouseCoopers LLP.

     99.1            Berkeley Networks, Inc. Substitute Stock Option Plan.
[{"type": "S-8", "sequence": "1", "description": "FORE SYSTEMS, INC.", "secsgml_size_bytes": 18368}]
{"company-data": {"conformed-name": "FORE SYSTEMS INC /DE/", "cik": "0000920000", "assigned-sic": "3576", "irs-number": "251628117", "state-of-incorporation": "DE", "fiscal-year-end": "0331"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-64359", "film-number": "98715416"}, "business-address": {"street1": "1000 FORE DRIVE", "city": "WARRENDALE", "state": "PA", "zip": "15086-7502", "phone": "4127726600"}, "mail-address": {"street1": "1000 FORE DRIVE", "city": "WARRENDALE", "state": "PA", "zip": "15086-7502"}}
1
      AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON SEPTEMBER 25, 1998

                                                         Registration No. 333-

===============================================================================
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                   ----------

                                    FORM S-8

                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933
                                   ----------

                               FORE SYSTEMS, INC.
             (Exact Name of Registrant as Specified in Its Charter)

          DELAWARE                                      25-1628117
(State or Other Jurisdiction of             (I.R.S. Employer Identification No.)
 Incorporation or Organization)

           1000 FORE DRIVE
       WARRENDALE, PENNSYLVANIA                                     15086-7502
(Address of Principal Executive Offices)                            (Zip Code)

              BERKELEY NETWORKS, INC. SUBSTITUTE STOCK OPTION PLAN
                            (Full Title of the Plan)

                                 THOMAS J. GILL
                      PRESIDENT AND CHIEF EXECUTIVE OFFICER
                               FORE SYSTEMS, INC.
                                 1000 FORE DRIVE
                       WARRENDALE, PENNSYLVANIA 15086-7502
                     (Name and Address of Agent for Service)

                                 (724) 742-4444
          (Telephone Number, Including Area Code, of Agent for Service)

                         Copy of all communications to:
                             CHRISTOPHER H. GEBHARDT
                 VICE PRESIDENT, CORPORATE COUNSEL AND SECRETARY
                               FORE SYSTEMS, INC.
                                 1000 FORE DRIVE
                       WARRENDALE, PENNSYLVANIA 15086-7502
                                 (724) 742-7658

                         CALCULATION OF REGISTRATION FEE
====================================================================================================================================

                                                                  PROPOSED MAXIMUM        PROPOSED MAXIMUM           AMOUNT OF
                                              AMOUNT TO BE       OFFERING PRICE PER      AGGREGATE OFFERING        REGISTRATION
 TITLE OF SECURITIES TO BE REGISTERED          REGISTERED             SHARE(1)                PRICE(1)                FEE(1)
------------------------------------------------------------------------------------------------------------------------------------
COMMON STOCK, PAR VALUE $.01 PER SHARE
BERKELEY NETWORKS, INC. SUBSTITUTE STOCK     618,999 shares           $20.0315               $12,399,479              $3,658   
OPTION PLAN
====================================================================================================================================
(1)  Estimated solely for the purpose of calculating the registration fee;
     computed in accordance with Rule 457(h) on the basis of the average of the
     high and low sales prices for the Common Stock on September 18, 1998 as
     reported on The Nasdaq National Market.
===============================================================================
2

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.

         The following documents filed by FORE Systems, Inc. (the "Company")
with the Securities and Exchange Commission (the "Commission") are incorporated
by reference into this Registration Statement on Form S-8 (the "Registration
Statement"):

         1.       The Company's Annual Report on Form 10-K for the fiscal year
                  ended March 31, 1998;

         2.       The Company's Quarterly Report on Form 10-Q for the fiscal
                  quarter ended June 30, 1998;

         3.       The Company's Current Report on Form 8-K dated September 11,
                  1998;

         4.       The Company's Current Report on Form 8-K/A dated September 11,
                  1998; and

         5.       The description of the Company's Common Stock, par value $.01
                  per share ("Common Stock"), contained in the Company's
                  Registration Statement on Form 8-A under the Securities
                  Exchange Act of 1934 (the "Exchange Act"), including any
                  amendment or report filed for the purpose of updating such
                  description.

         All documents subsequently filed by the Company with the Commission
pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act after the
date of this Registration Statement, but prior to the filing of a post-effective
amendment to this Registration Statement which indicates that all securities
offered by this Registration Statement have been sold or which deregisters all
such securities then remaining unsold, shall be deemed to be incorporated by
reference into this Registration Statement. Each document incorporated by
reference into this Registration Statement shall be deemed to be a part of this
Registration Statement from the date of the filing of such document with the
Commission until the information contained therein is superseded or updated by
any subsequently filed document which is incorporated by reference into this
Registration Statement or by any document which constitutes part of the
prospectus relating to the Berkeley Networks, Inc. Substitute Stock Option Plan
meeting the requirements of Section 10(a) of the Securities Act of 1933, as
amended (the "Securities Act").

ITEM 4.  DESCRIPTION OF SECURITIES.

         The class of securities to be offered under this Registration Statement
is registered under Section 12(g) of the Exchange Act.

ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.

         The validity of the shares of Common Stock to be issued under this
Registration Statement will be passed upon for the Company by Morgan, Lewis &
Bockius LLP, Pittsburgh, Pennsylvania. As of September 25, 1998, Marlee S.
Myers, a partner of Morgan, Lewis & Bockius LLP, held options to acquire up to
40,000 shares of Common Stock.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.

         Section 102(b)(7) of the Delaware General Corporation Law (the "DGCL")
permits a corporation, in its certificate of incorporation, to limit or
eliminate, subject to certain statutory limitations, the liability of directors
to the corporation or its stockholders for monetary damages for breaches of
fiduciary duty, except for liability (a) for any breach of the director's duty
of loyalty to the corporation or its stockholders, (b) for acts or omissions not
in good faith or which involve intentional misconduct or a knowing violation of
law, (c) under Section 174 of the DGCL or (d) for any transaction from which the
director derived an improper personal benefit. Article Eighth of the Company's
Amended and Restated Certificate of Incorporation, as amended, provides that the
personal liability of directors of the Company is eliminated to the fullest
extent permitted by Section 102(b)(7) of the DGCL.

                                      II-1
3

         Under Section 145 of the DGCL, a corporation has the power to indemnify
directors and officers under certain prescribed circumstances and subject to
certain limitations against certain costs and expenses, including attorneys'
fees actually and reasonably incurred in connection with any action, suit or
proceeding, whether civil, criminal, administrative or investigative, to which
any of them is a party by reason of his being a director or officer of the
corporation if it is determined that he acted in accordance with the applicable
standard of conduct set forth in such statutory provision. Article V of the
Company's Second Amended and Restated By-Laws provides that the Company will
indemnify any person who was or is a party or is threatened to be made a party
to any threatened, pending or completed action, suit or proceeding by reason of
the fact that he is or was a director, officer, employee or agent of the
Company, or is or was serving at the request of the Company as a director,
officer, employee or agent of another entity, against certain liabilities, costs
and expenses. Article V further permits the Company to maintain insurance on
behalf of any person who is or was a director, officer, employee or agent of the
Company, or is or was serving at the request of the Company as a director,
officer, employee or agent of another entity against any liability asserted
against such person and incurred by such person in any such capacity or arising
out of his status as such, whether or not the Company would have the power to
indemnify such person against such liability under the DGCL. The Company
maintains directors' and officers' liability insurance.

ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED.

         Not Applicable.

ITEM 8.  EXHIBITS.

         The following exhibits are filed herewith or incorporated by reference
as part of this Registration Statement:
EXHIBIT NO.                                           DESCRIPTION
------------         ---------------------------------------------------------------------------------
4.1             Amended and Restated  Certificate  of  Incorporation  of FORE Systems,  Inc. (as
                     amended  by  Certificate  of  Amendment  dated  May 6,  1996)  (incorporated  by
                     reference to Exhibit 3.1 to the Company's Annual Report on
                     Form 10-K for the fiscal year ended March 31, 1996).

     4.2             Second Amended and Restated By-Laws of FORE Systems, Inc.
                     (as amended through March 5, 1997) (incorporated by
                     reference to Exhibit 3.2 to the Company's Annual Report on
                     Form 10-K for the fiscal year ended March 31, 1997).

     5.1             Opinion of Morgan,  Lewis & Bockius  LLP as to the  legality  of the  securities
                     being registered (filed herewith).

    23.1             Consent of Morgan,  Lewis & Bockius LLP  (included  in opinion  filed as Exhibit
                     5.1).

    23.2             Consent of PricewaterhouseCoopers LLP (filed herewith).

    23.3             Consent of PricewaterhouseCoopers LLP (filed herewith).

    24.1             Power  of  Attorney  (set  forth  on the  signature  page of  this  Registration
                     Statement).

    99.1             Berkeley Networks, Inc. Substitute Stock Option Plan (filed herewith).
ITEM 9.  UNDERTAKINGS.

         (1) The undersigned registrant hereby undertakes: (i) to file, during
any period in which offers or sales are being made, a post-effective amendment
to this Registration Statement to include any material information with respect
to the plan of distribution not previously disclosed in the Registration
Statement or any material change to such information in the Registration
Statement; (ii) that, for the purpose of determining any liability under the
Securities Act, each such post-effective amendment shall be deemed to be a new
registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof; and (iii) to remove from registration by means of a
post-effective amendment any of the securities being registered which remain
unsold at the termination of the offering.

                                      II-2
4

         (2) The undersigned registrant hereby undertakes that for purposes of
determining any liability under the Securities Act, each filing of the
registrant's annual report pursuant to section 13(a) or section 15(d) of the
Exchange Act that is incorporated by reference in the Registration Statement
shall be deemed to be a new registration statement relating to the securities
offered therein, and the offering of such securities at that time shall be
deemed to be the initial bona fide offering thereof.

         (3) Insofar as indemnification for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of the registrant pursuant to the foregoing provisions, or otherwise, the
registrant has been advised that in the opinion of the Commission such
indemnification is against public policy as expressed in the Securities Act and
is, therefore, unenforceable. In the event that a claim for indemnification
against such liability (other than the payment by the registrant of expenses
incurred or paid by a director, officer or controlling person of the registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Securities Act and will be governed by the final
adjudication of such issue.

                                      II-3
5

                                   SIGNATURES

         Pursuant to the requirements of the Securities Act, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the Borough of Warrendale, Commonwealth of Pennsylvania on
September 25, 1998.

                                          FORE Systems, Inc.

                                      By: /s/ THOMAS J. GILL
                                          -------------------------------------
                                          Thomas J. Gill
                                          President and Chief Executive Officer

         KNOW ALL MEN BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Eric C. Cooper and Thomas J. Gill, and
each of them, his true and lawful attorneys-in-fact and agents, with full power
of substitution and resubstitution, for him and in his name, place and stead, in
any and all capacities, to sign any and all amendments to this Registration
Statement, and to file the same, with all exhibits thereto, and other
documentation in connection therewith, with the Commission, granting unto said
attorneys-in-fact and agents full power and authority to do and perform each and
every act and thing requisite and necessary to be done in and about the
premises, as fully to all intents and purposes as he might or could do in
person, hereby ratifying and confirming all that said attorneys-in-fact and
agents, or their substitute or substitutes, may lawfully do or cause to be done
by virtue hereof.

         Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed by the following persons in the capacities and on the
dates indicated.
Signature                                    Title                                     Date
              ---------                                    -----                                     ----
/s/ ERIC C. COOPER                   Chairman and a Director                                September 25, 1998
  ------------------------------
  Eric C. Cooper

  /s/ THOMAS J. GILL                   President and Chief Executive Officer (Principal       September 25, 1998
  ------------------------------       Executive Officer) and a Director
  Thomas J. Gill                                                          

  /s/ ROBERT D. SANSOM                 Senior Vice President and Chief Technical              September 25, 1998
  ------------------------------       Officer and a Director
  Robert D. Sansom                                              

  /s/ BRUCE E. HANEY                   Senior Vice President and Chief Financial              September 25, 1998
  ------------------------------       Officer (Principal Financial Officer)
  Bruce E. Haney                                                              

  /s/ GARY J. BRUNNER                  Vice President, Controller and Treasurer               September 25, 1998
  ------------------------------       (Principal Accounting Officer)
  Gary J. Brunner                                                      

  /s/ JOHN C. BAKER                    Director                                               September 25, 1998
  ------------------------------
  John C. Baker

                                       Director                                               September 25, 1998
  ------------------------------
  Daniel W. McGlaughlin

                                       Director                                               September 25, 1998
  ------------------------------
  Daniel R. Hesse

  /s/ JOHN T. LAMACCHIA                Director                                               September 25, 1998
  ------------------------------
  John T. LaMacchia
6

                                  EXHIBIT INDEX

 EXHIBIT NO.                          DESCRIPTION
 -----------         -----------------------------------------------------
      5.1            Opinion of Morgan, Lewis & Bockius LLP.

     23.2            Consent of PricewaterhouseCoopers LLP.

     23.3            Consent of PricewaterhouseCoopers LLP.

     99.1            Berkeley Networks, Inc. Substitute Stock Option Plan.