Iptables Port Redirection

How to redirect to another port on the same server:

iptables -t nat -A PREROUTING -p tcp -i eth0 -d $SERVER –dport 25 -j DNAT –to $SERVER:2525

Redirect a port to another server ($SERVER2):

iptables -t nat -A PREROUTING -p tcp -i eth0 -d $SERVER1 –dport 25 -j DNAT –to $SERVER2:25
iptables -A FORWARD -p tcp -i eth0 -d $SERVER2 –dport 25 -j ACCEPT
iptables -t nat -A POSTROUTING -d $SERVER2 -p tcp –dport 25 -o eth0 -j MASQUERADE
iptables -A FORWARD -p tcp -i eth0 -s $SERVER2 –sport 25 -j ACCEPT
iptables -t nat -A POSTROUTING -p tcp -s $SERVER2 –sport 25 -j SNAT –to $SERVER1

1 thought on “Iptables Port Redirection

  1. wooot, yeah, wow!

    after searching the net and hours of digging into more or less useless “how to do it with a dynamic dsl and masquerading” , i found this easy and short example! thats exactly what i need!

    Thx!Thx!Thx!

Leave a Comment