configuring ISDN as backup for serial Interface(s)

[raju]

Hello,

I have two leased lines (LL1 & LL2) backed by an ISDN line and all are terminating in a single Router.Both the leased lines are going to the same customer, but different locations. My requirement is , the ISDN should get fired when both the leased lines are down means when LL1 goes down, LL2 will become active and when LL1 & LL2 both are down , ISDN should get fired.Pls note that we are not doing any load balancing between LL1 & LL2 . LL2 will be standby mode only (higher metric using static route)and ISDN should get fired when both the LL are down. How to configure this in serial interface ?

Regards,

Raju

[ankurbhasin]

Hi Raju,

As per your statement the second LL2 will only be active when primary goes down as you are using static route with different metric. So according to me the isdn should only come up when your LL2 goes down.

When LL2 goes down we can configure backup interface for your isdn to trigger.

Just have a look at this link for backup dialer config

http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fdial_r/drfacas.htm#wp1018511

If LL2 comes back up your isdn will come down if you configure backup delay and other config as given in the link but if your LL1 comes up you have to manually bring the isdn down.

HTH, if yes please rate the post.

Ankur