Yes. I included in my original post. I include my read on it as well. ----- begin of the trace ------ 1 0.000000 192.168.1.6 192.168.1.7 WCCP 1.0 Here I am -----> Squid tries to register with the router. 2 0.000960 192.168.1.7 192.168.1.6 WCCP 1.0 I see you -----> Router sees it and registers it. 3 3.408431 10.17.11.20 209.131.36.158 TCP 34121 > http [SYN] Seq=0 Len=0 MSS=1460 TSV=100191619 TSER=0 WS=2 -----> Client tries to access a web site and the router forwards it to the Squid machine. 4 3.408469 192.168.1.6 204.146.97.xx ICMP Destination unreachable (Protocol unreachable) -----> Here I think indicates the problem which is the ip_gre doesn't know how to decapsulate the gre-ed WCCP packet. It send an ICMP packet back to the router with Protocol unreachable error. ----- end of the trace ------ Thanks again for your help. On Thu, 2006-08-03 at 22:00 +0200, Henrik Nordstrom wrote: > If you run tcpdump -n -i wccp0, do you see any traffic? > > Regards > Henrik > > tor 2006-08-03 klockan 12:03 -0700 skrev Arnold Wang: > > Yes, I did change those system settings mentioned in FAQ, including > > enabling routing, etc. > > > > [awang@xxxxxxxxxxxxxxxxx awang] > > $cat /proc/sys/net/ipv4/conf/wccp0/rp_filter > > 0 >