JNCIS-SP: Juniper Networks Certified Specialist – Service Provider Routing — Question 39

You are logged in to an MX80 and issue the command "show route protocol bgp" You see that you have received the route 10.0.4/24 from two different peers.
One peer is an external peer and the other is an internal peer. The route received from the internal peer is active.
By the rules of BGP preference, what would cause the internal path for this prefix to be preferred over the external one?

Answer options

• A. Internally learned prefix is preferred over an externally learned prefix
• B. The local-preference value of the internally learned prefix is higher than the externally learned peer
• C. The peer ID of the internally learned prefix is lower than that of the externally learned peer
• D. The internally learned prefix has a shorted cluster length

Correct answer: B

Explanation

The correct answer is B because BGP uses the local-preference value to determine which route to prefer when multiple routes to the same prefix exist. In this case, the internal route has a higher local-preference value, making it preferred over the external route. Options A, C, and D do not apply in this context as they do not address the local-preference value, which is the key determinant for preference in BGP.