4A0-112: Nokia IS-IS Routing ProtocolDemo

By Nokia · Question Mode

QuestionQ21

SR OS Control Plane Security

A router is attempting to establish an IS-IS adjacency with the DIS over a broadcast link. Which event causes the adjacency to transition from Initializing to UP?

  • A Receiving a Hello packet from the DIS that contains the local router’s own MAC address in the neighbor list.
  • B Receiving the first CSNP packet from the DIS that lists the LSPs in the DIS’s link-state database.
  • C Receiving a CSNP packet from the DIS acknowledging the last transmitted LSP.
  • D Receiving the last LSP requested from the DIS.
Explanation

For an IS-IS broadcast-LAN adjacency, the transition to Up occurs when the neighbor’s LAN IS-to-IS Hello includes the local router’s LAN address/MAC address in its neighbor list. This confirms bidirectional Hello communication; CSNP and LSP exchanges are link-state database synchronization mechanisms, not the condition for this adjacency-state transition.

Learn more

Community Discussion

No comments yet. Be the first to start the discussion!