OSPF Load-Sharing thru MPLS & GRE

[Firoz1981]

Hi,

Please refer attached. In here am trying to advertise few networks over OSPF through MPLS link and few through GRE tunnel. Am not able to get the configuration for the scenario. Any hints or help on configuration would be much appreciated.

Objective:

1. For e.g. 10.10.10.x/24 should be using MPLS link and 10.10.20.x/24 should be using GRE Tunnel.
   
2. routers should be in a single area (Area 1)
   
3. routers should be using single process id (Process 1)
   
4. If any link fails, the advertised route's should be using the second link (Failover). For e.g we are advertising 10.10.10.x thorugh MPLS, and if MPLS link drops, then 10.10.10.x & .20.x should be reachable through GRE Tunnel. The same applies the other way round for 10.10.20.x & .10.x networks.
   

Am not sure if am postig on a wrong Forum, please route me if so.

Thanks.

[ashok_boin]

Hi Firoz,

It's difficult as you will have a single area and so a single database.

The simple solution would be utilzing another routing protocol like RIP over GRE tunnel.

Regards..

-Ashok.

[Joseph W. Doherty]

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Posting

OSPF doesn't lend itself to doing what you require with the restrictions you've also noted.  You could also accomplish it, I believe, by using PBR with OSPF, although dealing with failure can be a bit tricky.

For situations like yours, I often ask - why do you want to do this? 

[Firoz1981]

Hi Joseph,

No special reason. Just want to achieve it. Anyways.. I was trying the below;

---------------------------------------------------------

route-map OSPF permit 110

description TAKES-GRE-TUNNEL0

match ip address 30

set metric +10

set interface Tunnel0

route-map OSPF permit 112

description TAKES-MPLS-FA0/0

match ip address 20

access-list 30 permit 10.10.20.0 0.255.255.255

access-list 20 permit 10.10.10.0 0.255.255.255

access-list 20 permit 10.10.20.0 0.255.255.255

----------------------------------------------------------

But it doesnot take T0. Metric gets changed for 10.10.20.x, but its is learning through FA0/0. Any hints where I can change the metric and route through T0?

Thanks.