It really depends if that is all the traffic you have you can just use floating static.
ip route b1 to l1
ip route b1 to l2 10
ip route b1 to l3 20
ip route b2 to l1 10
ip route b2 to l2
ip route b2 to l3 20
Now if you have traffic that is say A2 to B1 you can't use this method.
The generic method for source based routing is called policy based routing (PBR). Now in your case you want the policy routing to change if a line fails. Untill very recently that was almost impossible to do. With the new track options you can do this but it is still a complex configuration
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.