2611 Router FE FailOver

[swilson]

Hi All,

I'm having a 2611 Router on which we are getting the Internet on Fastethernet and parallely we are using ISDN BRI as a fall back.

Since the Internet connection is coming via Fastethernet, even though when the link is down, there is no "Line Up, porotocol Down" hence we cant use the "Backup Interface" command or the Floating Static Route to get the automatic failover to ISDN BRI.

Any help / suggestion will be quite helpful

Regards,

Wilson Samuel

[ziutek]

What about dialer watch? Setup the router to monitor a route in the routing table, and when it drops, the BRI comes up.

Joe

[swilson]

Thanks Joe, but unfortunately we are using Static Routes, and I believe the Dialer Watch will not be of quite good help, still will try on the suggestion.

Regards,

Wilson Samuel

[tbaranski]

Until the ability to actively monitor routes (via ping, for example) makes its way into the 12.3T train, which sounds at least a few months away, ziutek's suggestion may be your best bet if your ISP will let you run a routing protocol such as BGP with them.

If you can't run a routing protocol, a new feature in 12.3(4)T which allows active monitoring of policy-routing next-hops (http://www.cisco.com/en/US/products/sw/iosswrel/ps5207/products_feature_guide09186a00801d1e95.html) may suffice. You should be able to configure the 2611 to policy route everything out the FE interface when that next-hop is reachable; and when it becomes unreachable, to route out the ISDN interface. Note however that policy-routing everything may entail a performance hit -- I wouldn't expect a dramatic hit since PBR uses CEF by default in recent code versions, but it's something that you may want to test to be safe.

[ziutek]

I found this which is pretty intereresting:

http://ertw.com/faq/cache/30.html

Haven't actually tried this, but it is an interesting idea. Make the dialer backup watch the tunnel interface.

Let us know how you progress.

Joe