Alcatel-Lucent NRS I – Interior Routing Protocols and High Availability — Question 26

In IS-IS database synchronization, each router compares each LSP described in the received CSNPs with the LSPs in its own database. Which of the following actions is taken if the database contains a newer copy of the LSP?

Answer options

• A. The router sends a copy of the LSP from its database to its neighbor
• B. The router sends a PSNP to its neighbor describing the LSP in its database.
• C. The router updates its database with the LSP and floods a copy to its other neighbors.
• D. The router sends a PSNP to its neighbor to request the LSP.

Correct answer: A

Explanation

The correct action is to send a copy of the LSP from its database to its neighbor because this ensures the neighbor has the most current information. The other options are incorrect as sending a PSNP to describe or request an LSP does not address the need to share the newer version, and updating the database alone without notifying the neighbor does not maintain synchronization.