Unanswered Question
Mar 20th, 2009

Hi All

Is it possible to creat a backup route using policy based routing.For example I need to route internet browsing thru ADSL link .once it fails these traffic should go thru Internet leased line.Thanks in advance

I have this problem too.
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Jon Marshall Fri, 03/20/2009 - 05:01

PBR probably isn't the solution here but you can use floating statics ie.

ip route

ip route 250

note the 250 at the end of the second statement. This means this route will only be used if the first route is not in the routing table. If the ADSL link fails then the original route should be removed and the route pointing to the Internet leased line should be used.

If the ADSL link comes back up then the route will be installed in the routing table again.


anva12345 Fri, 03/20/2009 - 05:37

Hi Jon

Thanks for the quick response.My rquirement is all the outbound traffic shouild go thru ADSL link and all the inbound traffic and their return traffic should go thru leased line.Is it possible to configure without PBR.

Also I need to send the outbound traffic thru leased line when ADSL link fails?

Laurent Aubert Fri, 03/20/2009 - 06:39


The issue with ADSL link is your L3 interface is a Dialer interface which state is not linked to the physical interface state (Dialer interface are always UP).

So a standard default static route is not enough, you need to add a tracking object which will ping your hub public address. If the ping fails, this route will be removed and your backup default route (the one with the administrative distance set to 250 as suggested by John) will be installed and used.

Check this link for object tracking configuration:


Now regarding the inbound traffic, there is nothing you can do on the ADSL router. You need to configure a preferred route for the leased line on the peer router.




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