I can't make iptables forward a port.

[pessimist]

I'm obviously losing my marbles here. I'm running a fully updated F10 installation with the LTSP system installed on top. I want to use squid as a transparent proxy and so wish to forward port 80 to port 3128.

I've produced a (very) cut down script to initialise iptables as follows;

iptables -F
iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 3128
iptables -A INPUT -i eth0 -p tcp --dport 80 -j ACCEPT
iptables -A INPUT -i eth0 -p tcp --dport 3128 -j ACCEPT
iptables -L

The output is as follows:

Chain INPUT (policy ACCEPT)
target prot opt source destination
ACCEPT tcp -- anywhere anywhere tcp dpt:http
ACCEPT tcp -- anywhere anywhere tcp dpt:squid

Chain FORWARD (policy ACCEPT)
target prot opt source destination

Chain OUTPUT (policy ACCEPT)
target prot opt source destination

i.e. the forward doesn't happen. I had hair at the beginning of the day, I now have little left I'm obviously doing something stoopid but I haven't a clue what.

Anyone any ideas?

[sideways]

I think the third rule should say FORWARD not INPUT

[pessimist]

I think you're right. My brain hurts. Thank you!