Multi-homing / ISP Failover without BGP

[jb6846]

We are building out a new datacenter and have 1 x physical connection with a /30 for each pair of ASR routers, one for the incoming traffic pair and one for the outgoing pair. The ISP will not provide a second line from the same subnet, nor will it give us anything larger than a /30.

Are there any other options than BGP?

The only other option they gave us was to have us go down a BGP route, but we would have to get that from a Tier 1 Service Provider and have it cross-connected into the cage. We would have to do this for both pairs.

[cpubob]

I am not exactly sure I understand your topology or what you are trying to accomplish, but you can add a static route with a "track" object. This would allow your static default to go away if the track object fails.

If, for example, you have two next-hop routers and you want to use one as primary and the other as a backup, you could do something like this, assuming 192.168.1.1 is primary and 192.168.2.2 is secondary. It will ping the primary router every 15 seconds. If the ping fails, the route is removed and the floating static route will take over to the secondary router.

ip route 0.0.0.0 0.0.0.0 192.168.1.1 track 100

!

ip route 0.0.0.0 0.0.0.0 192.168.2.2 200

!

track 100 rtr 1 reachability

!

ip sla 1

icmp-echo 192.168.1.1

frequency 15

timeout 30

!

ip sla schedule 1 life forever start-time now

!

Check out this doc for more info.

http://www.cisco.com/en/US/docs/ios/12_3/12_3x/12_3xe/feature/guide/dbackupx.html

HTH,

-Rob

Please rate if helpful. Thanks