changes in our relationship with EMC Corporation (EMC), International Business Machines Corporation (IBM), Hitachi Data Systems (HDS), Hewlett-Packard (HP) and our other distribution partners and the level of their orders

Exhibit 10.80

Wilson Sonsini Goodrich & Rosati

PROFESSIONAL CORPORATION

650 Page Mill Road
Palo Alto, CA ###-###-####

phone ###-###-####

fax ###-###-####
www.wsgr. com

September 11, 2006

Via Certified Mail

Luther Orton
Snyder Miller & Orton LLP
111 Sutter Street, Suite 1950
San Francisco, CA 94104

Re:

Tolling Agreement Entered Into As of January 1, 2006 between Gregory L. Reyes on the one hand and Brocade Communications Systems, Inc., (“Brocade”), David House, William Krause, Nicholas Moore, William O’Brien, Christopher Paisley, Larry Sonsini, Seth Neiman, Neal Dempsey and Sanjay Vaswani, on the other (the “Tolling Agreement”)

Dear Luther:

     Pursuant to the Tolling Agreement, notice is hereby given that David House, William Krause, Nicholas Moore, William O’Brien, Christopher Paisley, Larry Sonsini, Seth Neiman, Neal Dempsey and Sanjay Vaswani (collectively the “Directors”), hereby terminate that agreement solely as to themselves. Brocade, on the other hand, is not terminating the Tolling Agreement. Accordingly, while all periods of limitation (statutory or otherwise) will begin to run again forty-five (45) days from the date of service of this notice upon you as to any claims or causes of action which Reyes may have against the Directors or which any of them may have against Reyes, the statute of limitations remains tolled on any claim which Reyes may have against Brocade or which Brocade may have against Reyes.

cc: Richard Marmaro (via Electronic Mail)