Mailserver / 2 Internet Connections

[csmager]

For the second time in the space of 5 weeks, my BT line has completely died - no dial tone or DSL. I run my mail server off this connection, so it's a bit of an irritation when it dies - though my emails are hardly critical (hence it's not hosted offsite and managed properly!).

Just got to thinking - if I had a second connection as a backup (e.g. 3G, or my neighbour's Wi-Fi), how would you go about setting this up?

My router supports multiple WAN interfaces, so this shouldn't be an issue. My issue is with MX records and having two different Public IPs. Would you just list it as an MX record with lower priority? Then should it simply be ignored when the main connection is back up?

Any insights welcome!

 

[tolien]

That would work, but you'll find mail comes into the backup MX even when the primary is up (though in 99% of cases you can reject it).

 

[Skidilliplop]

You wouldn't need multiple WAN ports on the router, just connecting the Server's Wifi card to a neighbours wifi or plugging in a 3G modem should be fine. The DNS records will only be aware of the WAN IPs of you and the other connection so there's no need for them to physically terminate at your router, Unless you want to load balance them when they both work.

 

[csmager]

You wouldn't need multiple WAN ports on the router, just connecting the Server's Wifi card to a neighbours wifi or plugging in a 3G modem should be fine. The DNS records will only be aware of the WAN IPs of you and the other connection so there's no need for them to physically terminate at your router, Unless you want to load balance them when they both work.

I see what you mean - my idea was that if the router worked, it could route everything via the backup connection if the main one failed (failover).

BT fixed the line yesterday afternoon, so I might delay doing this till another day. Hopefully BT won't cut me off again!

 

[Skidilliplop]

It depends what your server is running, your server itself is probably capable of failover. If it's server 2003 it'll support load balancing, I'm sure linux will do it too, and probably better.
XP might do it, perhaps manually if you can set an administrative distance on a static route.