Alcatel-Lucent NRS I – Interior Routing Protocols and High Availability — Question 25

In IS-IS, which of the following statements regarding an L1/L2 router is false?

Answer options

• A. An L1/L2 router can have neighbors in different areas.
• B. An L1/L2 router calculates separate SPF trees for the Level 1 and Level 2 topology.
• C. An L1/L2 router advertises its L2 routes to its L1 neighbors.
• D. An L1/L2 router sets the ATT bit in L1 LSPs to identify itself as an L1 router.

Correct answer: D

Explanation

The correct answer is D because an L1/L2 router does not set the ATT bit in L1 LSPs to indicate itself as an L1 router; this is specifically done by an L1 router. Options A, B, and C are true statements about L1/L2 routers and their functionalities in IS-IS.