wan load balancing

[pvontobel]

The wan I am talking about is build arround two major ressources sites A & B then I have 6 big remote centers which are each connected to the points A & B by four pvc (each major ressource center is equiped with two routers in order to ensure full backup) then I have 10 small remote centers connected to the major A & B by two PVC's.

Right now, I am using EIGRP & access-list, but the use of the bandwitdth is very poor.

What do you suggest to do in order to have a good WAN, build arround standby, load balancing & automatic rerouting if any line goes down.

[donewald]

EIGRP actually does a pretty good job of load balancing equal cost paths. The design problems that most see is where the data comes into the network from is the same and one "best" path is chosen. If your routers, that provide connections to you hosts, use HSRP with multiple groups/interfaces try to distribute this (i.e. if you have 10 groups do 5 primary on 1 and 5 on the other). In this way you'll get a more distributed load due to the entry point changing. This is all assuming that these are equal cost links (show ip eigrp top x.x.x.x where x.x.x.x is your destination prefix will show you the EIGRP metric for the route)

If not equal cost you can use EIGRP variance command to allow for unequal cost load sharing.

Also a factor is the type of switching you are using in your routing devices. If all cisco there is fast switching and CEF that are mostly used. These effect load balancing depending on how implemented.

Route-maps with a "set ip next-hop x.x.x.x" can be used to force certain traffic matched by ACL down a certain path.

Hope some of this helps you out,

Don