Trying to migrate server traffic with iptables

Hi,

I'm moving several domains from one box to another. I'd like to use
iptables to redirect traffic from the old server to the new server
while the DNS propagation catches up. I was successfully using xinetd
to redirect the traffic, but my mailserver requires that the IP address
on the incoming SMTP, POP, and IMAP packets match the server IP. I
think that iptables can do this, can someone confirm this? If so, what
commands do I need to use? I've read a lot of firewall scripts and am
getting confused with SNAT, DNAT, postrouting and prerouting. Any
guidance here would be appreciated.

(E-Mail Removed) wrote:
> Hi,
>
> I'm moving several domains from one box to another. I'd like to use
> iptables to redirect traffic from the old server to the new server
> while the DNS propagation catches up. I was successfully using xinetd
> to redirect the traffic, but my mailserver requires that the IP address
> on the incoming SMTP, POP, and IMAP packets match the server IP. I
> think that iptables can do this, can someone confirm this? If so, what
> commands do I need to use? I've read a lot of firewall scripts and am
> getting confused with SNAT, DNAT, postrouting and prerouting. Any
> guidance here would be appreciated.
>

use SNAT and FORWARD rules! These will forward the traffic appropriate.
If you post an usecase, we're posting examples. Otherwise try "man
iptables".

Eric