Which three configuration changes will create a summary route?

Exhibit

A network designer would like to create a summary route as shown in the exhibit, but the configuration is not working.

Which three configuration changes will create a summary route? (Choose three.)
A . set policy-options policy-statement leak-v6 term DC-routes then reject
B . delete policy-options policy-statement leak-v6 term DC-routes from route-filter 2001: db9:a: fa00 : :/6l longer
C . set policy―options policy-statement leak-v term DC―routes from route-filter 2001:db9:a:faOO::/61 exact
D . delete protocols isis export summary-v6
E . set protocols isis import summary-v6

View Answer

Answer: B,C,D

Explanation:

To create a summary route for IS-IS, you need to configure a policy statement that matches the prefixes to be summarized and sets the next-hop to discard. You also need to configure a summary-address statement under the IS-IS protocol hierarchy that references the policy statement. In this case, the policy statement leak-v6 is trying to match the prefix 2001:db9:a:fa00::/61 exactly, but this prefix is not advertised by any router in the network. Therefore, no summary route is created. To fix this, you need to delete the longer keyword from the route-filter term and change the prefix length to /61 exact. This will match any prefix that falls within the /61 range. You also need to delete the export statement under protocols isis, because this will export all routes that match the policy statement to other IS-IS routers, which is not desired for a summary route.