Controlling HTTP & SMTP IP flow for 3 NIC's

[Tim Alberts]

John Summerfield wrote:
> Tim Alberts wrote:
>> A little background first..I run 2 servers, mail and web.  The mail 
>> server is down for hardware problems.  I'm running both email and web 
>> on one server.  The web server has 3 network interfaces 1 for public 
>> email, 1 for public web, and 1 for private network.  I use 3 cards 
>> because the router I connect to the internet won't recognize multiple 
>> IP's for a single hardware MAC.
>>
>> The problem is, that my email messages seem to be going out the web 
>> network interface.  This is typically not a problem except for the 
>> reverse DNS lookup  fails which at least one domain (Comcast.Net) 
>> rejects.
>>
>> My question therefore is, how can I route my sendmail traffic to go 
>> out the correct ethernet interface?  I'm sure I'll need to do the 
>> same for the web traffic so web site spoofing alarms are triggered.
>>
>> I have told sendmail to listen to the correct interfaces, but that 
>> apparently doesn't mean only write to those interfaces.  I don't see 
>> how to control this by setting up my routes and I can only really 
>> think of ways to block it in IPtables, not re-route it.
>>
>
> The problem arises in part because of the complexity of the network.
>
> I run several servers (smtp, ssh, www, imap), and they all work 
> perfectly well from a single IP address, so I wonder, Why do you need 
> so many?
Please refer to the several times I've explained, the router provided by 
my ISP is not accepting virtual IP addresses.

>
> In some cases, the services are served from different boxes; ssh to 
> where I work and it terminates on my desktop, smtp on another goes to 
> one server or another, depending on where you are. It's how I receive 
> email to this address from some locations, but _you_ can't email to it.
>
>
>