2 gwia's 1 Post office

Question

Hello all:
Our ISP, Verizon Business, can be unreliable at times. The T1 circuit seems to go down during heavy rain storms, before heavy rain storms, and once every 3 months.
For fault tolerance, the plan is to add another gwia to our Post Office via another ISP . We are thinking that if the first line goes down, the MX record will point to the second gwia and we should be ok for email.
We are still on GW7.03. Are there any hicups to note with this setup? Any pointers (other than moving to Unix or GW8) to offer?
Thanks

Answer 1

Originally Posted by EBSR_PARAMEDIC
Hello all:
Our ISP, Verizon Business, can be unreliable at times. The T1 circuit seems to go down during heavy rain storms, before heavy rain storms, and once every 3 months.
For fault tolerance, the plan is to add another gwia to our Post Office via another ISP . We are thinking that if the first line goes down, the MX record will point to the second gwia and we should be ok for email.
We are still on GW7.03. Are there any hicups to note with this setup? Any pointers (other than moving to Unix or GW8) to offer?
Thanks
It depends... Is your current GWIA on "the inside" or directly connected to the internet?
if you are NAT'ing an outside address from your providers to the GWIA, there is not a direct need to add a second GIWA. Just make sure the outside IP of you second internet connections has a NAT for the SMTP port pointing to your GIWA.
Make sure they add the second ip record to the outside MX record of your mail exchange domain, and that should be set.
You can setup your GWIA to smart relay to more than one address. Just add the two outgoing addresses (a space to separate them) on the GWIA's outbound host. That should let the GWIA use the first one until if fails and then fall back to using the second one. (As found here : Novell Documentation)
One thing to watch could be the outside IP on your second internet line and if it matches the FQDN name your GWIA is reporting. If those two don't match up according to the internet DNS records, your mail might be dropped as it is seen as possible spam attempt. So I'd advise to give the failover a good test before counting on it fully working when needed.
Cheers,
Willem