How do routers elect "Designated Web-cache" in WCCP environment?

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Updated:August 12, 2014

Document ID:118241

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Question:

How do routers elect "Designated Web-cache" in WCCP environment?

Environment: Cisco Web Security Appliance (WSA) used with WCCP redirection

Election of the designated web-cache will take place once a Service Group membership has established, during initial handshake or following a change. The designated web-cache must be receiving a WCCP2_I_SEE_YOU message from every router in the Service Group.

Election of the designated web-cache is not part of the WCCP protocol.

Below IETF draft describes version 2.0 of the Web Cache Communication Protocol (WCCP)

https://tools.ietf.org/id/draft-wilson-wrec-wccp-v2-01.txt

Typically it is recommended that the web-cache with the lowest IP address be selected as designated web-cache for a Service Group.

While using WSA with WCCP redirection on Cisco routers, WSA with the lowest IP address will be elected as Designated Web Cache (DWC).