When ProxySG sends ICAP packets to an ICAP server, X-Client-IP and X-Server-IP are being added in the ICAP header. Why does it happen?
You can select ICAP send options on ICAP service editor window (from ProxySG Management Console > Configuration > External Services > ICAP , select ICAP service, then click Edit, and under the ICAP v1.0 Options box, check/uncheck Send options> OK > Apply).
The Send optionsallow additional information to be forwarded to the ICAP server. Select one or more of the following: Client address, Server address, Authenticated user, or Authenticated groups.
If you have checked "Client address" and "Server address," ICAP send options on your ProxySG; the ProxySG will add the information before it sends ICAP packet to ICAP server.