EXHIBIT 32.1

              CERTIFICATION OF CHAIRMAN AND CHIEF EXECUTIVE OFFICER
                  PURSUANT TO 18 U.S.C. SECTION 1350 AS ADOPTED
            PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

    I, Scott Kriens, certify, pursuant to 18 U.S.C. Section 1350, as adopted
pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that the Quarterly
Report of Juniper Networks, Inc. on Form 10-Q for the three months ended June
30, 2004 fully complies with the requirements of Section 13(a) or 15(d) of the
Securities Exchange Act of 1934 and that information contained in such Quarterly
Report on Form 10-Q fairly presents in all material respects the financial
condition and results of operations of Juniper Networks, Inc.

/s/ Scott Kriens
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Scott Kriens
Chairman and Chief Executive Officer
August 5, 2004