EXHIBIT 5

                    OPINION AND CONSENT OF BROBECK, PHLEGER & HARRISON LLP

                                  July 19, 2002

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

        Re: Cisco Systems, Inc. - Registration Statement for Offering of an
            aggregate of 2,129,311 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
(a) 2,013,271 shares of the Company's common stock for issuance under the
Hammerhead Networks, Inc. 2000 Omnibus Stock Plan and (b) 116,040 shares of the
Company's common stock for issuance under the Navarro Networks, Inc. 2000 Stock
Plan (collectively, the "Plans").

        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 assumption of the Plans
and the outstanding options thereunder. 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
option agreements duly authorized under the Plans 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
Plans or the shares of the Company's common stock issuable under such plans.

                                  Very truly yours,

                                  /s/ BROBECK, PHLEGER & HARRISON LLP

                                  BROBECK, PHLEGER & HARRISON LLP