Your network has an OSPF area that connects to an EIGRP area at two points, Router A and Router B. You directed your assistant to set up these two routers in order to have traffic load-balanced between the two entry points. However, you discover that all traffic is going through Router A. When you view the results of the show run command for each device, you get the partial output shown below:
What action should be performed to make traffic use both routes to the EIGRP area?
- change the metric for EIGRP to 50 on Router A
- change the metric for EIGRP to 45 on Router B
- change the metric type to Type 1 on Router A
- change the metric type to Type 1 on Router B
You should change the metric for EIGRP to 50 on Router A. The metric can be defined when configuring the redistribution of one routing protocol into another. A lower metric will cause traffic to be routed in that direction. Therefore, to make the paths from the two routers equal, you should raise the metric on Router A to 50 to match that of Router B.
You should not lower the metric on Router B to 45. It will still be a higher metric than that of A and traffic will still go in that direction.
You should not change the metric type on either router. The metric type determines whether the downstream OSPF routers should add their cost to the total cost to get to the ASBR when computing cost. In this scenario, Router A and Router B are both ASBRs. When set to Type 1, downstream OSPF routers do add their metric. With Type 2, they simply use the configured metric. If you want true load balancing, you should leave the metric type set to Type 2, since you have no information on the cost from the other routers to the ASBRs. However, when Type 1 is used, you must also take into consideration the metric from the other routers to the ASBR when determining the true cost to leave the OSPF area.
Layer 3 Technologies
Configure and verify redistribution between any routing protocols or routing sources