squid透過プロキシ

acl localip src 192.168.13.0/255.255.255.0
http_access allow localip
httpd_accel_host virtual
httpd_accel_port 80
httpd_accel_uses_host_header on
httpd_accel_single_host off

iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 3128
と/etc/sysctl.conf