Cisco Systems Completes Acquisition of Riverhead Networks

SAN JOSE, Calif., April 15, 2004 – Cisco Systems, Inc., today announced it has completed the acquisition of privately held Riverhead Networks of Cupertino, Calif.

On March 22, 2004, Cisco announced a definitive agreement to acquire Riverhead, a leading developer of security technology that protects against Distributed Denial of Service (“DDoS”) attacks and other security threats in enterprise and service provider networks. This acquisition further enhances Cisco’s Self Defending Network strategy of deploying proactive, self-defending, and self-healing networks, and building advanced security into the network infrastructure.

About Cisco Systems
Cisco Systems, Inc. (NASDAQ: CSCO) is the worldwide leader in networking for the Internet. Information on Cisco can be found at http://www.cisco.com. For ongoing news, please go to http://newsroom.cisco.com.

Cisco, Cisco Systems, and the Cisco Systems logo are registered trademarks of Cisco Systems, Inc. and/or its affiliates in the U.S. and certain other countries. All other trademarks mentioned in this document are the property of their respective owners.