Solaris

Hi ......
I'm trying to configure my Solaris servers with only one NIC card to have 2 IP addresses as well as 2 different default gateways.

( NOT to be confused with multi-pathing - with 2 physical IPs & 1 virtual ip)

Thanks,
Remi

From a routing perspective, how would you expect two default routes to work? The point of a defaut route it that if I don't know how to contact an address I ask the default router to do for me, if I have two, which one do I ask?

Solaris will allow you do so, and it is within specs but it is a very bad idea, becasue it will round-robin between the routes.

To go even further, Solaris ( prior to Solaris 10 anyway, I havn't look at this in the new stack ) would round-robin your data at the packet, not the stream, so you could have packets arriving at destination from mutiple routes which depending on the traffic may cause application issues. It is a particularly bad idea if your machine is multi-homed.

When you then add network fabric such as firewalls etc into the mix, the routing simply becomes non-deterministic. In other words it might work, it might not, or it might work for a while then stop working.

If you are looking at this from the point of view of having a backup default rout in case one fails you would be better of running a dynamic routing process.