port forwarding

[Cristian M.]

Anyone knows or have some examples how to make port forwarding on Linux RedHat 7.3 using ipchains?
I've tried something like that:
"iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 21 -j DNAT --to 192.68.10.11" but i got an error:
"iptables v1.2.5: can't initialize iptables table `nat': iptables who? (do you need to insmod?)"

[Jerome Henry · Accepted solution]

Do you use ipchains or iptables ? On rh7.3, iptables by default. Ipchains is the older version.
Your message shows that you use iptables, which is normal.
Your error message means that nat table is not known. Your should write NAT instead.
Check also that there is no conflict between Ipchains and Iptables :
service ipchains stop
chkconfig ipchains off
rmmod ipchains

service iptables start
chkconfig iptables on
insmod iptables.
HTH
J

[Cristian M.]

Well, i'm using ipchains. I thought i can use both ipchains and iptables at the same time. I didn't find any possibilities to make 'port forwarding' using ipchains so i guess i have to use iptables from now on...

[Jerome Henry]

Yes you will... Ipchains is not supported anymore in the further releases...
You may be used to Ipchains, but you'll see that Iptables is better, and quite easy to use.
Read this paper on that :
www.linuxguruz.org/iptables/ howto/iptables-HOWTO-7.html
RGDS
J