Which description of the possible cause of issues in the routing domain is true?

A network consultant is troubleshooting IS-IS instances to identify why a routing domains is having communication problems between the two instances.

Which description of the possible cause of issues in the routing domain is true?
A . The same interface cannot be advertised in two different IS-IS instances
B . The IS-IS “ISP” and “ISP2” instances are unrelated and unable to intercommunicate
C . The configured IS-IS NSEL value is not allowing the routing systems to establish a neighborship
D . The interface mode ip router is-is command was not included in the script

View Answer

Answer: A

Explanation:

Reference: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_isis/configuration/xe-3s/irs-xe-3s­book/irs-instance-vrf.html