Re: PAT HOW to - IPTABLES

>> Suppose, I have 3  mail servers @ DMZ zone with one real ip. the situation
>> as before?
>>
>> in that case, What can I do?
>>     
> your could use exim/postfix and route the mail to the right server, but I guess 
> you are trying to find out how to have port 25 on the real ip nat'ed to one of 
> the 3 dmz'ed ip based upon the destination mail address
>
> short answer you can't as far as I know, iptables only looks at src ip / src 
> port & dest ip/dest port.  You could write your own plugin module to look into 
> the tcp stream.
>   

based upon destination email address/domain could be done by postfix and 
transports for selected mail/domain to selected server. but there is 
also a possibility of load balancing and failover for set of domains 
with all servers working with all the domains for HA and flexibility of 
computing power, then id say take a look at keepalived for both those 
features. for http traffic its actually the same, and also you can 
consider apache reverse proxy feature.

-- 
Radek aka Goblin