I have two routers connected point-to-point by two serial links. i want to load balance with OSPF so that i can run PBR and classify a certain type of traffic to use a single serial and another type to use another serial based on destination ip address. is this possible with OSPF, how can I configure that?
Also, it is important to note that in my above example there is no verify-availability on the route map's next hop. This means that if a T1 goes down, the router would still be trying to route over it based on the route map. OSPF wouldn't, but the route map would not detect that the T1 is down and therefore would still be setting next hop.
So, if you provide specifics on exactly what you want to do, I can help with configs. Mainly, tell me what traffic you want to use which T1's.
For example, lets say you have voice, web, and ftp traffic. You want to use one T1 for only voice traffic. However, if that T1 goes down, you want the voice to be able to failover to the other T1.
Or, another example. Lets say you have voice, web, and ftp traffic. You want FTP and web to use both T1's, however, you only want voice to be able to use the first T1.
Try to be specific as possible. Obviously, you can replace your real subnets with bogus private IP's if you would like.
Okay, take a look at the attached drawing, it is a very basic configuration of how PBR works. Effectively, when traffic comes into interface Gi0/1, if it matches some condition (could be route-source, subnet, DSCP values, or a bunch of other various things). So, if it matches the first condition in sequence number 10 of the route-map, then it goes across the 1st T1. If not, it would check the traffic to see if it matches sequence number 20 of the route map. If it does, then it would go across the 2nd T1. If it didn't match either, then normal routing would occur. In other words, a routing table lookup would happen. OSPF may have 2 equal cost routes (one over each T1) in which case it would load balance the traffic. However, don't be confused on how the load balancing occurs. It is not per packet (i.e. its not like the first packet uses the 1st T1 and the 2nd uses the 2nd). I believe, by default, that a computation occurs based on source and destination IP addresses. If the result is "even" it would use the 1st T1. If the result is "odd" it would use the 2nd. Does that make more sense?