[CentOS] Port Forwarding

Hi,

To implement either 1) or 3) you need to mix iptables and iproute2 to
route packages matching specific criteria.

The "Linux Advanced Routing & Traffic Control HOWTO" has a specific
section on this, and an example very similar to yours (although they
show how to route outgoing e-mail traffic and not incoming).

See this URL:
http://lartc.org/howto/lartc.netfilter.html

However, I still think you should re-evaluate your requirements, think
of what you're trying to accomplish, and re-architecture your solution
based on that.

HTH,
Filipe