Traffic Engineering over dual MPLS ISPs

[Jesus Crespo]

Hi Everyone,

I'm trying to configure redundancy over 2 MPLS networks. Both providers are running BGP and peering with our core using OSPF.

I need to configure the routing in a way that traffic from network 10.10.1.0/24 to 10.1.1.0/24 goes via ISP1 and if ISP1 is down to fail over to ISP2.

Traffic from 10.11.1.0/24 to 10.2.1.0/24 goes via ISP2 and if ISP2 goes down to fail over to ISP1.

ISP routers are doing mutual redistribution BGP to OSPF and OSPF to BGP.

Is this scenario possible on the current topology?

What will be the best way to configure it?

[Jon Marshall]

On the HQ router what do the Branch routes look like in the IP routing table ? 

Are they showing as OSPF E2 routes ?

Jon

[Jesus Crespo]

E1 routes redistributed from BGP into OSPF

[Jon Marshall]

So you are setting the external type as you redistribute ?

I ask because by default redistributed routes into OSPF show as E2.

Regardless of that the easiest way would be to redistribute as E1s for the ISP connection you want to prefer and then redistribute the same routes as E2s on the ISP connection you want as a backup.

E1s are preferred over E2s so it should automatically use the preferred ISP unless it fails and then it will use the other.

You would need to do this on both sides of the connection if you want to make sure your return traffic follows the same path.

Jon

[e.ciollaro]

You'right Jon but I'm not sure ISP's will change the type of redistribution "on-demand";  netvoixinc are your ISP going to change on request ?

Another strange thing is that having the same Area in both sites, the subnets should be redistributed as inter-area not external.

In any case traffic from both network (10.10.1.0 10.11.1.0) will use the same path, so you balance traffic but not based on source network, isn'it ?

If both network are directly connected to the routers PBR is requested to change the path based on source network or, maybe, PfR.  netvoixinc are the networks directly connected or they are behind some other router not showed in the picture?