a discussion starter i hope.

[alan barrow <aaa.coms.sec@btclick.com>]

I have been using iptables-netfilter for a while and wish to clarify in
my mind for once how to do the following. 

Scenario: An iptables firewall has 2 interfaces, which are a public and
a private interface, for simpilicty's sake. Behind the firewall a
service runs which needs to be visible to the world at large in this
case let's start with an easy one http, on port 80. 

No problems so far :) 

Now behind the firewall are 2 separate servers, each running a web
service and each running on port 80. 

1) The question is, with only 1 real world address available to you,
what suggestions do you guy's have as to the configuration required to
make both web servers available on the Internet ? So that incoming port
80 request on the firewall public interface go to the correct server. 

2) The same as scenario 1) except you have 2 addresses available but
only one external NIC. 

3) Same as 2) except you have 2 NIC's. 

The reason for this is the following is that, i wish to understand if
there is a path to this result. I realise there are probably many way's
to skin this cat, and i have tried a few of them, some of you may
already be doing this, but in my experience there seem to be a lot of
pitfall's and consequently the issues i have faced seem to suggest the
following: 

Some think it's possible, Some don't, some wish it was possible, many
just say this way, others suggest that way, many just give up. 

All in all i would like to take this to the logical conclusion of
getting it working in multiple scenarios securely and effectively. 

yours a.r.b.