WAN Routing Scenario

[dtran]

Hi all, I have a WAN routing scenario and hope someone can help.

I have two routers, one is connected to a Point-to-Point link and the other is connected to an MPLS link and both links can be used to get back to the data center. The scenario I am running into is that the Pt-to-Pt link is always the prefer link even when traffic hits the MPLS router it will get routed over to the Pt-to-Pt router to exit out to the WAN. How could I manipulate the routing topology so that when traffic hits the MPLS router it will use the MPLS link to the WAN. EIGRP is the routing protocol being used.

Thanks all in advance !!!

Danny

[Julio E. Moisa · Accepted solution]

Hi

As I understand you want to pass traffic through the MPLS from the MPLS router and not use the P2P, is that correct? You could use route-maps with set ip next hop.

[dtran]

Hi Julio, thanks for your response !!

Yes, that's correct Julio. So when traffic arrives on the MPLS router send it out to the MPLS link instead of routing the traffic back to the Pt-to-Pt router.

I am trying to avoid using route-map in this scenario. Could I manipulate EIGRP routing metrics in this scenario ?

Thanks !!

Danny

[Bibin Paul]

Hi,

The answer is YES

Check the "show ip eigrp topology" and can use appropriate delay or bandwidth.

Bibin

[Joseph W. Doherty · Accepted solution]

Additionally, if you're using EIGRP, you should be able to (if you wish) to (statically) proportionally route across both paths.

If you equipment supports it, PfR would also allow (dynamic) proportional routing across both paths.

[Masoud Pourshabanian · Accepted solution]

Hello,

As Bibin suggested, you can easily use delay. Increase the delay of P2P interface. Just you need to be careful when you use EIGRP in this scenario. Unlike OSPF, EIGRP does not have any mechanism to avoid routing loop.

To see that, pick  a subnet on your router(for example 10.10.10.0/24)

Show IP EIGRP 1 topology 10.10.10.0/24.

You see that there are two entries.

1- local

2-Coming from MPLS or p2p( it means local routes will be advertised and come back from other side.

To avoid that you need to use SSO( Site Of Origin) in EIGRP.

Hope it helps,

Masoud