It seems that you have not create GRE tunnel successfully. You can try this: # ifconfig gre0 create # ifconfig gre0 link0 tunnel squid_host_IP router_IP up where: router_IP is IP address of routers physical interface (not loopback interface) Besides, I noticed that with IOS 12.x, if you enable CEF(Cisco Express Forwarding) for the interface which redirects the packets, something weird will happen. Sometimes no packets redirect to your squid box at all, sometimes only truncated or fragmented GRE packets arriving at the cache. Apparently it works if you disable Cisco Express Forwarding for the interface: conf t ip cef # some systems may already have 'ip cef global' int Ethernet 0/0 (or int FastEthernet 0/0 or other internal interface) no ip route-cache cef CTRL Z Regards, Bin
