Installation guide

A router may also use Layer 2 (L2), which does not use GRE. Websense recommends
the use of L2 if the router supports it. With L2 redirection, Content Gateway must be
on the same subnet as the WCCP device (that is, Layer 2 adjacent).
A proxy and a router communicate via a set of WCCP “Here I am” and “I see you”
messages. A proxy that does not send a “Here I am” message for 30 seconds is
removed from service by the router, and client requests that would have been directed
to that proxy are sent to another proxy.
The following figure shows some components of Websense Content Gateway in a
transparent proxy deployment: