Tadek’s Blog

iptables -t nat -I PREROUTING -p tcp --destination-port <other port> -j REDIRECT --to-ports 25

• redirecting incoming packets to other ports

  iptables -t nat -I POSTROUTING -o -http://lists.netfilter.org/pipermail/netfilter/2004-March/051478.htmlj MASQUERADE

• all packets that would go through internet connected interface will be maqueraded

I recently found out that this redirect doesn’t work for traffix generated to the local interface. Following the advice from this list I made it to work (I don’t know if you need some special kernel options as they suggested it just worked for me on 2.6.x).

iptables -t nat -I OUTPUT -p tcp --destination-port <other port> -o lo -d localhost -j REDIRECT --to-ports 25

This entry was posted on Tuesday, October 19th, 2004 at 11:34 am and is filed under Security, Tips&Tricks. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.