Les Mikesell 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.
That's fairly bizarre if true. Are you sure it didn't just fail
temporarily when you switched because the previous MAC was cached?
Routers typically keep their arp cache for up to 20 minutes and won't
re-discover a moved IP/NIC sooner unless you manually clear the cache.
But... you'd have the same issue with aliases on the same NIC.
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.
You probably used the DaemonPortOptions entry in sendmail.mc to
control the listening side. Do the same with ClientPortOptions for
outbound connections.
Boy it sure sounded like a solution. This may guarantee that sendmail
sends on the specified IP interfaces. However I think the underlying
linux routing is still the problem because the problem hasn't gone away.
