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                                    EXHIBIT 5

             OPINION AND CONSENT OF BROBECK, PHLEGER & HARRISON LLP


                                  June 1, 1999


Cisco Systems, Inc.
170 West Tasman Drive
San Jose, California  95134-1706

     Re:  Cisco Systems, Inc. -- Registration Statement for Offering of
          75,152,534 Shares of Common Stock

Dear Ladies and Gentlemen:

     We have acted as counsel to Cisco Systems, Inc., a California corporation
(the "Company"), in connection with the registration on Form S-8 (the
"Registration Statement") under the Securities Act of 1933, as amended, of
75,152,534 shares of common stock (the "Shares") and related stock options under
the Company's 1996 Stock Incentive Plan (the "Incentive Plan").

     This opinion is being furnished in accordance with the requirements of Item
8 of Form S-8 and Item 601(b)(5)(i) of Regulation S-K.

     We have reviewed the Company's charter documents and the corporate
proceedings taken by the Company in connection with the establishment and
amendment of the Incentive Plan Based on such review, we are of the opinion that
if, as and when the Shares are issued and sold (and the consideration therefor
received) in accordance with the Incentive Plan and in accordance with the
Registration Statement, such Shares will be duly authorized, legally issued,
fully paid and nonassessable.

     We consent to the filing of this opinion letter as Exhibit 5 to the
Registration Statement.

     This opinion letter is rendered as of the date first written above and we
disclaim any obligation to advise you of facts, circumstances, events or
developments which hereafter may be brought to our attention and which may
alter, affect or modify the opinion expressed herein. Our opinion is expressly
limited to the matters set forth above and we render no opinion, whether by
implication or otherwise, as to any other matters relating to the Company, the
Incentive Plan, or the Shares issuable under the Incentive Plan.


                                        Very truly yours,

                                        /s/ BROBECK, PHLEGER & HARRISON LLP
                                        -----------------------------------
                                        BROBECK, PHLEGER & HARRISON LLP

