2008-07-23 04:22:10 -

www.f5.com - F5 Networks, Inc. (NASDAQ:FFIV): -0- TOPIC: F5 Third Quarter Financial Results DATE: Wednesday, July 23, 2008 TIME: 1:30 PM Pacific (4:30 PM Eastern) DIAL IN NUMBER: 800-857-3834 (US & Canada) +1-210-839-8222 (International) CALL LEADER: John McAdam PASSCODE: F5 NETWORKS

Please call in 10 minutes ahead of time to ensure a proper connection. We

look forward to having you join us. If you have any problems or questions, please call F5 NETWORKS, INC. (206) 272-5555. -0- REPLAY INFORMATION Replay Via Phone: Available July 23, 2008 (from 4:30pm Pacific) through July 24, 2008 (until 5:00pm Pacific) Phone: 800-216-3086 (US & Canada) 402-220-3765 (International) Replay Via Internet: www.f5.com/about/investor- relations/events-calendar.html Available until October 22, 2008

F5 Networks, Inc., Seattle
John Eldridge, 206-272-6571 (Investor Relations)
j.eldridge@f5.com