Linux - Redirect Ports Using IPTables

In order to redirect ports, we need to add our rules in PREROUTING chain. So run below command:

[[email protected] ~]# iptables -t nat -A PREROUTING -i ens18 -p tcp --dport 80 -j REDIRECT --to-port 8080

If we have an interface name other than ens18 then we need to edit we command accordingly. We can even add we source and destinations as well in same command using --src and --dst options. Without them, it’s assumed to any source and any destination.

Check port redirection in iptable

Verify port redirect rule in iptables using below command:

[[email protected] ~]# iptables -t nat -L -n -v
Chain PREROUTING (policy ACCEPT 1 packets, 30 bytes)
pkts bytes target     prot opt in     out     source               destination
84  5000 REDIRECT   tcp  --  ens18  *       0.0.0.0/0            0.0.0.0/0            tcp dpt:80 redir ports 8080

We can see port 80 is being redirected to port 8080 on the server. Note here target is REDIRECT. Do not get confused with port redirection with port forwarding.

Save IPTables rules

To save iptables rules and make them persistent over reboots use the following command:

[[email protected] ~]# iptables-save