Let me explain my current setup.
Our current Postfix setup for outgoing e-mail uses three different
entries for different type of e-mail from our university. This is
accomplished by three different names, e.g. smtp1.example.com,
smtp2.example.com and smtp3.example.com, pointing to three different
ip-addresses. Every ip-adresses is load-balanced to two different
servers. Per server there are three different ip-adresses, all listening
on port 25. Obviously every instance has it's own Postfix configuration.
No rocket science so far; this works for years, and very well.
In the new setup, our networking department wants to get rid of the
three different ip-adresses per server. Instead they want to 'stack' all
the traffic comming from the load-balancer on one ip-address, but on
different ports, say 1025, 2025 and 3025. (Needless to say the three
different ip-adresses on the front-side of the load-balancer are being
continued.)
Most likely this setup will work, but I'm not very happy with it. It's
more difficult to split logging and set-up of the host-based firewall
(if applicable) is more difficult. The configuration of Postfix will be
different from the current setup so it takes more time to adjust.
However, all these items seem kind of 'cosmetic'. Therefor I would like
to know if there are more consequences of this setup. Is there a
technical reason which would prohibit this setup?
Awaiting your answers.
Regards, Willy Janssen
