[CentOS] OT - IP Tables - forwarding to localhost

Luciano Rocha strange at nsk.no-ip.org
Mon Jun 18 11:09:46 UTC 2007


On Mon, Jun 18, 2007 at 11:46:42AM +0100, first last wrote:
> Hi,
> 
> I am trying to set up a firewall rule so calls to old_mailserver:25 get
> redirected to localhost:25. I have seen quite a few rules and none seem
> to work.
> 
> I have tried with the firewall enabled (configured to allow smtp) and
> disabled, but it doesn't seem to make a difference.
> 
> One of the commands I have been using is:
> /sbin/iptables -t nat -I PREROUTING -p tcp -d old_mailserver_ip/32
> --dport 25 -j REDIRECT --to 127.0.0.1:25

Try this:
iptables -t nat -I PREROUTING -p tcp -d old_mail_server_ip --dport 25 \
  -j REDIRECT
iptables -t nat -I OUTPUT -p tcp -d old_mail_server_ip --dport 25 \
  -j REDIRECT
 
> Am I missing anything?

Locally generated packets go through OUTPUT, but not PREROUTING, IIRC.

-- 
lfr
0/0
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