We have a CentOS 4.4 box with something like the following IPs:

eth0: 64.61.61.100

eth0:0 64.61.61.112

eth1: 10.0.0.100

lo: 127.0.0.1 (of course)

We want requests to 64.61.61.112:80 to be NAT'ed to 127.0.0.1:8080.

This seems like it should be really simple -- maybe the following? -- I've tried variants combining this rule with a POSTROUTING rule, tried dnat, snat, etc. -- but no luck.

echo 1 > /proc/sys/net/ipv4/ip_forward

iptables -t nat -A PREROUTING -i eth0 -p tcp -m tcp -d 64.61.61.112 --dport 80 -j DNAT --to-destination 127.0.0.1:8080

The box's iptables are rather vanilla -- pretty much the standard "allow ssh, http" in (I added 8080 just to eliminate that as a possibility, too, even though 8080's only listened to on localhost).