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                                                                       EXHIBIT 5

             OPINION AND CONSENT OF BROBECK, PHLEGER & HARRISON LLP

                                February 23, 2001

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

Re:  Cisco Systems, Inc. - Registration Statement for Offering of
     341,864,605 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 an
additional 341,864,605 shares of the Company's common stock reserved for
issuance 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 with respect to the establishment and amendment
of the Incentive Plan. Based on such review, we are of the opinion that, if, as
and when the shares of the Company's common stock are issued and sold (and the
consideration therefor received) pursuant to the provisions of stock option
agreements duly authorized under 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 of the Company's common stock issuable under such
plan.

                                        Very truly yours,

                                        /s/ Brobeck, Phleger & Harrison LLP

                                        BROBECK, PHLEGER & HARRISON LLP

