I have found the following Kernel requirements: (http://wiki.squid-cache.org/SquidFaq/InterceptionProxy ) # # Code maturity level options # CONFIG_EXPERIMENTAL=y # # Networking options # CONFIG_FIREWALL=y # CONFIG_NET_ALIAS is not set CONFIG_INET=y CONFIG_IP_FORWARD=y # CONFIG_IP_MULTICAST is not set CONFIG_IP_FIREWALL=y # CONFIG_IP_FIREWALL_VERBOSE is not set CONFIG_IP_MASQUERADE=y CONFIG_IP_TRANSPARENT_PROXY=y CONFIG_IP_ALWAYS_DEFRAG=y # CONFIG_IP_ACCT is not set CONFIG_IP_ROUTER=y My Configuration (kernel 2.6.22-14) has the following set: CONFIG_EXPERIMENTAL=y ->check! CONFIG_FIREWALL=y CONFIG_IP_FIREWALL=y # CONFIG_IP_FIREWALL_VERBOSE is not set ->No options for FIREWALL. # CONFIG_NET_ALIAS is not set ->No options for NET_ALIAS CONFIG_INET=y ->Check! CONFIG_IP_FORWARD=y ->No Options for FORWARD # CONFIG_IP_MULTICAST is not set ->IP_MULTICAST IS SET CONFIG_IP_MASQUERADE=y ->CONFIG_IP_NF_TARGET_MASQUERADE is set to m CONFIG_IP_TRANSPARENT_PROXY=y ->No Options for TRANSPARENT_PROXY CONFIG_IP_ALWAYS_DEFRAG=y ->No Options for DEFRAG # CONFIG_IP_ACCT is not set ->No Options for IP_ACCT CONFIG_IP_ROUTER=y ->IP_ADVANCED_ROUTER=y I'm planning on compiling kernel 2.6.23-12 with the following options: CONFIG_EXPERIMENTAL=y CONFIG_INET=y FORWARD # CONFIG_IP_MULTICAST is not set CONFIG_IP_NF_TARGET_MASQUERADE = y IP_ADVANCED_ROUTER=y Any comments?