Basically, I m using two routers, router A and router B. Lease line on router A while ISDN on router B. On production time, only lease line is used as primary route. But, if lease line fails, all traffic will route to router B to trigger the ISDN. Really need all experts here to help on how to create the routing to establish this design. Thank you.
I believe that your requirements can be solved through HSRP and does not require any special routing logic. You will want to configure HSRP on the LAN interfaces. You will want to set priority so that router A with the leased line is the primary/active router and that router B is the standby (I suggest priority of 105 on router A and the default of priority 100 on router B). You will want to configure tracking on router A to track the serial interface. If the serial interface fails then router A will reduce its priority and you want the priority of router B to be higher than router A at this time. You will want to configure HSRP preempt on router B so that it can take over if the priority of router A is lowered. And you will want to configure preempt on router A so that when the leased line recovers that router A can resume as the active router.
If you configure those things I believe that you will satisfy your requirements.
You can use Dialer Watch for ISDN.
Sample configuration and more information here:
Config watches the routing table and presence of the route in there.
same url from Slidesv without cco login...
we can configure this thing in very simple way. configure the serial interface and for isdn configure BRI interface or creat the dialer and bind the dialer inside the serial interface as a backup line. give delay command. all traffic will go vis serial interface and once lease line will go down it will trigure the isdn to handle the traffic and once lease line will up again Lease line will take up the responsibility.
backup int d1
bacup delay 3 10
If you read the original post the leased line is on router A and the ISDN is on router B. Backup interface will not work when the primary is on one router and the backup is on another router.
I go with Rick recommendation. I have that setup in a production, works like a charm and no sweat at all. Unless you want to explore a more complicated configuration with dynamic routing, etc..
Here is some link.
If both lines in the same router
Each line in different router. I was planning this, until I found a simple setup using HSRP as what Rick recommended. In the LAN, since OSPF is use, it doesn't matter whether you use HSRP or not
Troubleshooting Demand Circuit keeps bringing up the link
Advantages and disadvantages