Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) — Question 241

FRR is configured on a network. What occurs when the headend router on the path is alerted to a link failure over IGP?

Answer options

• A. LSP attempts fast switching on the backup path until the primary path returns to the active state.
• B. The headend router uses a presignaled LSP to bypass the failure point.
• C. A new backup tunnel is established past the PLR to pass through the protected nodes.
• D. Backup tunnel is established and intersects with the primary tunnel at the headend.

Correct answer: B

Explanation

The correct answer is B because a presignaled LSP allows the headend router to immediately bypass the link failure without waiting for the link state to converge. The other options describe processes that either do not occur during a link failure or are not the primary method utilized in this scenario.