[rt-users] Tricky situation with rt-mailgate

[Jay R. Ashworth]

On Sun, May 01, 2005 at 11:00:30PM -0400, Tuc at Beach House wrote:
[ me: ]
> > Your problem was having the two machines that are the target of the
> > load-balancing be able to talk to one another without interference,
> > correct?
> >
> 	No.

Oh.  :-)

> 	There is a 3rd machine, also behind the load balancer because it
> is in the same subnet, that accepts the rt-mailgate traffic. Since it is
> in the subnet with the load balanced site name, it can not reference the
> load balanced name to work. There is a modification that we could make,
> but it would then make every hit for EVERY site behind the balancer show
> it originated from the same IP, which would be unacceptable.

So you're trying to get the mailgate box to talk to the other two,
with*out* going through the load-balanced IP address for those boxes,
right?

> > To do that, put in a second ethernet interfaces, *on a separate private
> > network than the one behind the load balancer*, and you might have to
> > play hosts-file name games to force the traffic to use that link.
> >
> > Sorry I wasn't sufficiently clear the first go-round.
> > 
> 	It comes back down to even with a 2nd interface, the load balanced
> IP is still in the subnet of the first interface.

Yes, but if you *lie* to the mailgate machine, by putting into it's hosts
file the name of the other machines, as well as their IP address *on
the other private network* (192.168.2/24, for example, where the load
balanced interfaces are on 192.168.1/24), then the mailgate machine
won't *talk* to the load balanced IPs.

In other words, set up a "back" network that the loadbalancer has no
knowledge of, and force the mail machine to use it.

Was that clearer, and do you think it will serve?

Cheers,
-- jra
-- 
Jay R. Ashworth                                                jra at baylink.com
Designer                          Baylink                             RFC 2100
Ashworth & Associates        The Things I Think                        '87 e24
St Petersburg FL USA      http://baylink.pitas.com             +1 727 647 1274

      If you can read this... thank a system administrator.  Or two.  --me