Ubuntu 12 iptables ignores nat rule?

Question

Following line is appears in several SO answers regarding how to serve node applications through port 80: the aadvice being given is to forward the traffic to an unprivileged port.

iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 3000

However, when I try this on Ubuntu 12.04 iptables helpfully does absolutely SFA. Nothing. Am I running afoul of an iptables version thing here?

Has anyone got a proven solution that will work on Ubuntu 12.04 et al.? Much appreciated.

Answer 1

Note that the -i eth0, means it will only work for things coming from the network eth0. So it won't work if you test it from localhost, and it won't work if your hardware is slightly different. Try removing the -i eth0 entirely.