I used manual http://wiki.squid-cache.org/ConfigExamples/TPROXYPatchingCentOS?highlight=%2 8centos%29%7C%285%5C.2%29 Centos 5.2 kernel 2.6.25.11 tproxy-kernel-2.6.25-20080519-165031-1211208631.patch <http://wiki.squid-cache.org/tproxy-kernel-2.6.25-20080519-165031-1211208631 .patch> tproxy-iptables-1.4.0 tproxy-iptables-1.4.0-20080521-113954-1211362794.patch Squid3-HEAD <http://www.squid-cache.org/Versions/v3/HEAD/> iptables -t mangle -N DIVERT iptables -t mangle -A PREROUTING -p tcp -m socket -j DIVERT iptables -t mangle -A DIVERT -j MARK --set-mark 1 iptables -t mangle -A DIVERT -j ACCEPT iptables -t mangle -A PREROUTING -p tcp --dport 80 -j TPROXY --tproxy-mark 0x1/0xffffffff iptables -t mangle -A PREROUTING -p tcp --dport 80 -j TPROXY --tproxy-mark 0x1/0x1 --on-port 3128 I didn't got problem with installation or compiling. I didn't used the wccp I manual set proxy ip in browser And got the address ERROR: IPInterception.cc(171) NetfilterTransparent: NF getsockopt(IP_TRANSPARENT) failed: (92) Protocol not available