Exhibit 32.1

CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER AND PRINCIPAL FINANCIAL OFFICER

PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906

OF THE SARBANES-OXLEY ACT OF 2002

I, Jayshree Ullal, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that the Annual Report of Arista Networks, Inc. on Form 10-K for the fiscal year ended December 31, 2014 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 and that the information contained in such Annual Report on Form 10-K fairly presents in all material respects the financial condition and results of operations of Arista Networks, Inc.

Date: March 11, 2015

By:	/s/ JAYSHREE ULLAL
Name:	Jayshree Ullal
Title:	Chief Executive Officer and President
	(Principal Executive Officer)

I, Kelyn Brannon, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that the Annual Report of Arista Networks, Inc. on Form 10-K fiscal year ended December 31, 2014 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 and that the information contained in such Annual Report on Form 10-K fairly presents in all material respects the financial condition and results of operations of Arista Networks, Inc.

Date: March 11, 2015

By:	/s/ KELYN BRANNON
Name:	Kelyn Brannon
Title:	Chief Financial Officer
	(Principal Accounting and Financial Officer)