[c-nsp] TE without MPLS question

[Oliver Boehmer (oboehmer)]

Nick Kraal <> wrote on Tuesday, June 13, 2006 6:04 AM:

> Dear all,
> 
> I have a situation here where some TE needs to be carried out. We have
> not implemented MPLS-TE in our network as yet.
> 
> CustA, CustB, etc
> | 
> RTRA----RTRB
> |        |
> RTRD----RTRD
> |
> BigBadWWW
> 
> [1] Router A-D are all full mesh iBGP speakers i.e. CustomerA and
>      CustomerB prefixes are directly announced to all routers from
> RTRA. [2] From OSPF link costs, the route path for CustomerA/B (to
>      get to RTRD for the Internet)is:
>       CustA->RTRA->RTRD->Internet
> [3] Link between RouterA and RouterD is now congested.
> [4] Is there a way to traffic engineer such that *only* CustomerA is
>      routed via:
>       CustA->RTRA->RTRB->RTRD->RTRD->Internet

If you modify your OSPF costs so RTRB will use only RTRD to reach RTRD
(oh, two times RTRD in your picture) instead of load-sharing between
RTRA and RTRD, you should be able to policy-route all traffic from CustA
on RTRA towards RTRB, and then RTRB uses the alternate path for the
traffic.

	oli