WCCP Service Groups

--> A service group combines one or more routers or switches with one or more caching devices for implementing transparent proxy deployment in the network.

--> Each and every member of the group need to agree on the rules by specifying their capabilities and configurations.

--> Each and every caching device in the service group sends “Here I Am” message to the routers in the group.

--> These message Contains protocol, ports to redirect, the method to use to forward and return packets to each other ( GRE or L2 Address Redirect).

--> The routers in the Service Group respond with an “I See You” message that includes a Receive ID as well as a list of WCCP capabilities such as forwarding/return methods that the router supports.

-->  The Caching appliance responds with another “Here I Am” message in which it reflects the Receive ID that was sent in the “I See You” message from the router.

--> Now both Router and Caching Appliance will verify the wccp capabilities they can support.

--> Each Caching Appliance in the Service group periodically sends out “Here I Am” messages to the routers in the group to maintain its service group membership.

--> If a router doesn’t receive a “Here I Am” message from a Caching Appliance in the group within the designated time-out interval, it removes the appliance from the service group.

Ref: Symantec And Cisco.com

Md.Kareemoddin

CCIE # 54759