MX records

[Barry Margolin]

In article <93l2f9$jsp at pub3.rc.vix.com>,  <c_c100 at my-deja.com> wrote:
>Hello all,
>
>Let me explain our setup first.  We have two internet connections(two
>ISP's--Diff IP addressing) going into our Firewall which has three Nic
>cards (one for internal network the other two our internet
>connections).  We have an MX record pointing to the external IP of our
>firewall.  All SMTP traffic is then redirected to a mail relay that has
>a private/internal IP.  Now what we want to do is utilize that other
>internet connection to the firewall just in case one of the lines goes
>down to still recieve our mail.
>What would be the proper MX records setup to this?
>
>This is pretty much our current setup.
>
>company.com      MX 100       mail.company.com
>mail.company.com    IN A     100.100.100.99
>
>Now we want to add that other internet connection with a different IP
>pointing to the same machine(firewall)/domain.
>
>would this be the proper way?
>
>company.com      MX 100       mail.company.com
>company.com      MX 200       mail2.company.com
>
>mail.company.com    IN A     100.100.100.99
>mail2.company.com    IN A     200.200.200.99
>
>Sorry if this is all over the place but just a bit confused :) and
>trying to be as thorough as I can :)

Yes, this is the right way to do it.

If you wanted to load share over both Internet connections, you could give
both MX records the same preference level.  Senders will pick one at
random, so you would expect that half the time they'll use one connection,
and half the time the other.  If either connection fails, the senders that
pick that one first will time out and then fail over to the other one.

-- 
Barry Margolin, barmar at genuity.net
Genuity, Burlington, MA
*** DON'T SEND TECHNICAL QUESTIONS DIRECTLY TO ME, post them to newsgroups.
Please DON'T copy followups to me -- I'll assume it wasn't posted to the group.