The real nuts and bolts of everyone’s IGP of choice, OSPF, are a bit complex, but strangely satisfying. After understanding how it works, we’re left wondering, “what else do we need?” Make sure to review the first part of our look at OSPF before embarking on this potentially confusing journey.
This article will cover LSA types, packet types, and area types. First, however, we’d like to dispel a common misunderstanding about dynamic routing:
People have a tendency to tinker with traffic, even when they aren’t suffering from under-provisioned bandwidth. In OSPF, you cannot really influence the way traffic is routed, aside from adjusting a path’s metric. Some routers support making changes to weights, but this isn’t usually necessary. OSPF generally takes care of assigning weights, based on the speed of the interfaces on a router. You can also use ECMP (equal cost multipath) with OSPF, if you have two links to the same place and wish to load balance in a round-robin fashion. Don’t try tinkering with OSPF parameters; more likely than not, if you think you have a problem it’s a network design issue, and fixing that will accomplish your goals.
http://www.linuxlinks.com/portal/news/article.php?story=20081029134731167