I am having an adjacency issue with Cisco devices, WCCP v2 and Linux-based squid 2.6. I am running a CentOS 5.1 box with the packaged Squid that comes with the ditribution. If I have a router redirecting to the squid box, and the squid box has a GRE tunnel setup to point to the "show ip wccp" advertised IP, the whole setup does not work. The moment I make the squid box layer2/layer3 adjacent to the "show ip wccp" advertised IP the whole setup works fine. I am allowing all GRE traffic, so I know it is not a firewalling issue, but I do notice that the linux box is not using the GRE tunnel because ifconfig shows no increase in packet counts. The commands I am using are as follows, and this is for WCCP/Transparent caching: **Note: the local ip of the squid box is 10.2.2.31, and 192.168.1.1 is the IP of the WCCP router. 192.168.1.1 is a Cat6506/Sup720, and 192.168.1.1 is a router link on that switch, 10.2.2.0/24 is a vlan with a router link on it, all on the same switch. /sbin/ip tunnel add gre0 mode gre remote 192.168.1.1 local 10.2.2.31 dev eth0 /sbin/ip addr add 10.2.2.31/32 dev gre0 /bin/echo 0 > /proc/sys/net/ipv4/conf/gre0/rp_filter /sbin/ip link set gre0 up /sbin/service squid start The WCCP router does not register the squid cache as being there, but a "debug ip wccp" shows the two talking to each other. This issue, in general, has been a problem on mulitple IOS versions, but I think it may be something wrong with the gre tunnel setup on the Linux box. Anyone have ideas as to what I may be doing wrong? Nick
