http://www.linuxhomenetworking.com/wiki/index.php/Quick_HOWTO_:_Ch32_:_Controlling_Web_Access_with_Squid



**Proxy transparente**
====== Puerto 80 ======
Instalar Squid y configurar la conexión a otro proxy:

  http_port <ip local>:3128 transparent
  cache_peer <ip proxy1> parent 3128 0 login=usuario:contrasenya no-query default round-robin
  cache_peer <ip proxy2> parent 3128 0 login=usuario:contrasenya no-query default round-robin

Por ejemplo:
  http_port 192.168.1.4:3128 transparent
  cache_peer 10.145.0.36 parent 3128 0 login=ca.lafou:qh76SPga no-query default round-robin
  cache_peer 10.145.2.34 parent 3128 0 login=ca.lafou:qh76SPga no-query default round-robin
  


====== Resto de puertos ======
Configuramos una conexión con el corkscrew por el puerto 443 a una VPN de un servidor en inernet 

  #! /bin/bash
  iptables -t nat -D PREROUTING -i br0 -p tcp --dport 80 -j REDIRECT --to-port 3128
  iptables -t nat -D POSTROUTING -o tun0 -j MASQUERADE
  iptables -t nat -A PREROUTING -i br0 -p tcp --dport 80 -j REDIRECT --to-port 3128
  route add -net 10.145.0.0 netmask 255.255.0.0 gw 192.168.1.1
  route del default
  route add -host 192.168.65.1 dev tun0
  route add default gw 192.168.65.1
  iptables -t nat -A POSTROUTING -o tun0 -j MASQUERADE


Corkscrew:
Fichero .ssh/config:
  Host calafouproxy
  Port 443
  ProxyCommand /usr/bin/corkscrew 10.145.0.36 3128 94.23.80.158 443 /home/caedes/.proxycalafou
  IdentityFile /root/.ssh/tunnel_key

OpenVPN
  client
  dev tun
  proto tcp
  remote 127.0.0.1r 1194
  resolv-retry infinite
  nobind
  persist-key
  persist-tun
  ca ca.crt
  cert seldon.crt
  key seldon.key
  #comp-lzo
  verb 3
  #cipher none
  script-security 2
  up /etc/openvpn/up.sh


Fichero /etc/openvpn/up.sh es el script del uptables

/etc/inetd.conf
  # ssh tunnel to smarthost.com's SMTP server
  127.0.0.1:1194  stream  tcp     nowait  root    /usr/bin/ssh  -q -T vpncalafou@calafouproxy