Last Updated on July 31, 2021 by Admin 1
You have two autonomous systems connected by more than one ASBR.
Which strategy does Cisco recommend in this situation?
- Use two-way redistribution.
- Use a default route in both directions.
- Allow routes to be exchanged in one direction, and use a default route in the other direction.
- Manually configure routes in all ASBRs, and update the configuration each time there is a change in either AS.
Explanation:
If there is a single autonomous system border router (ASBR) connecting two autonomous systems (AS), Cisco generally recommends full two-way route redistribution. But when there are multiple ASBRs, as in this scenario, two-way route redistribution may result in routing loops. One solution is to use a default route in one direction and allow routes to be exchanged in the other direction.Default routes in both directions will almost certainly cause routing loops.Manual configuration of static routes would work, but the administrative maintenance necessary when there are changes would be considerable.
If there is a single autonomous system border router (ASBR) connecting two autonomous systems (AS), Cisco generally recommends full two-way route redistribution. But when there are multiple ASBRs, as in this scenario, two-way route redistribution may result in routing loops. One solution is to use a default route in one direction and allow routes to be exchanged in the other direction.Default routes in both directions will almost certainly cause routing loops.Manual configuration of static routes would work, but the administrative maintenance necessary when there are changes would be considerable.
Objective:
Layer 3 Technologies
Sub-Objective:
Configure and verify redistribution between any routing protocols or routing sources