[cc lang='bash']
\$ apt-get install squid3
\$ iptables -t nat -A PREROUTING -i eth1 -p tcp -m tcp --dport 80 -j DNAT --to-destination 192.168.0.1:3128
[/cc]

/etc/squid3/squid.conf
[cc lang='bash']
http_port 3128 transparent
acl our_networks src 192.168.0.0/24
acl localnet src 127.0.0.1/255.255.255.255
http_access allow our_networks
http_access allow localnet
cache_dir ufs /var/spool/squid3 7000 256 1024
cache_peer web-main.proxy.intra parent 8080 0 login=user:pass no-query proxy-only
cache_peer web-backup.proxy.intra parent 8080 0 login=user:pass no-query default
[/cc]