[c-nsp] General Question to OSPF

[Oliver Boehmer (oboehmer)]

Ahmad Cheikh-Moussa <> wrote on Saturday, March 18, 2006 1:17 PM:

> Hi!
> 
> I made some thoughts about an ospf design.
> I would like to know, what other people think about it.
> 
> Here it is.
> I have 4 cisco routers. All of them are connected together
> in a ring topology. All connections have the
> same bandwith/delay and so on.
> The routers are connetcted via transfer networks
> and all of them are in area 0.
> Two of the four routers have uplinks to two BGP
> routers. Both BGP routers are the default gateways
> for the other 4 routers. The uplinks are
> separated in two transfer networks in area 0.
> 
> Is there something I should keep in mind, when I try
> such a configuration  ?
> What happens, when OSPF has several equal routes ?
> routing loops ??

Just enable OSPF as you described, and it will work. If you have
equal-cost paths, OSPF will install multiple paths into the RIB and the
router will load-share. There is no risk for loops if you let OSPF do
all the routing. 
You do need to take a look at your iBGP topology, though. If you don't
run BGP on all the transit routers, you could run into loops. But I miss
more detailed info about the BGP topology in order to evaluate this.

	oli