OSPF Redundancy Failover with Preferred Link over Dual DMVPN/ISPs

[hbaytie01]

Hi,

I have a scenario where I have a Head Office and a couple of branches, all of them have routers. I have to ISPs(MPLS) Providers.

Each router is connected to two ISPs (MPLS), and there is DMVPN configured on my routers for both MPLS clouds, in order for all the branches to reach other through a redundant scenario. I will use OSPF over my DMVPN(BGP) to advertise the subnets between branches. 

I'm supposed to receive the same subnet twice from each ISP via OSPF.

My first question is how can I force my router to use the first ISP to reach the branch subnet, can I change the metric of OSPF coming from the first ISP to make it the preferred one and what is the command, if you can post a small configuration example. 

The second question is if I'm able to force my router to use the first ISP and then this ISP went down and the now my router is using the second ISP link. once the first ISP link comes up, will the router go back to use the first ISP automatically or it will stick with the second, because I saw some posted problems related to this issue, where it doesn't fall back to the first ISP unless you clear the OSPF process.

Design Attached!!!!

Thanks in advance for your support

[Philip D'Ath]

Use "ip ospf cost ..." under the interface.  You can either make one interface look better or the other look worse.

http://www.cisco.com/c/en/us/support/docs/ip/open-shortest-path-first-ospf/13689-17.html

[paul driver]

Hello

Also could use metric type or max-metric router lsa to pefrom path manipulation 

res

paul