2 NICs, 2 ISPs, one instance of Sendmail, how will this work

[Elguapaul]

We have a sendmail server running and working fine. We recently added a second (failover) internet connection and I would like to configure our sendmail server to use the new connection in the event our main data line goes down.

I have already installed a second NIC. How do I configure Sendmail to listen on this new adapter as well?

How will Sendmail handle messages if/when the main data line fails. Will there be any issues with outgoing mail?

Cheers !!

 

[elgrandeperro]

It should already. Sendmail typically listens on all port 25 (wildcard) addresses, you can verify by using "netstat -an". You usually have to change it to not listen on an interface.

Inbound, you can change DNS MX precedence records so you can have a primary and secondary service.

Outbound, you are more likely to change the TCP routing which isn't a function of sendmail. The simple way is to change the default route by hand. A more immediate way is to use some routing protocols between your 2 routers.

 

[Elguapaul]

Thanks.. that is exactly the information I was looking for.

Cheers !!