Hi Shailesh, > Can you provide me with some more details to examine the Squid/ICAP > negotiation? > You can use tcpdump (or better wireshark) to examine squid/ICAP negotiation. Look Henriks notes about tcpdump usage here: http://marc.info/?l=squid-users&m=118936426216901&w=2 Maybe you can post some tcpdump info to allow squid developers to examine if it is a squid or ICAP server bug .... The ICAP protocol is HTTP based so I think it is easy to debug it. For the OPTIONS requests (which fails in your case) the squid must send something like this: OPTIONS icap://127.0.0.1:1344/reqmod ICAP/1.0 Host: 127.0.0.1:1344 And ICAP server should response with something like the following: ICAP/1.0 200 OK Methods: RESPMOD, REQMOD Service: ICAP server Transfer-Preview: * Options-TTL: 3600 Date: Tue, 11 Sep 2007 13:34:55 GMT Preview: 1024 Allow: 204 Encapsulated: null-body=0 Regards, Christos