mpls rsvp-te challenge-lost

Node A and node B are RSVP neighbors and they need to authenticate each other. Node A authenticates node B as follows:

1.Node A sends an RSVP message carrying an Integrity object to node B.

2.After node B receives the message and detects that the key ID of node A is different from the key ID in the Integrity object, node B sends a Challenge message to node A and starts a timer for retransmitting the Challenge message periodically and recording the resending times.

3.After node A receives the Challenge message from node B, node A directly copies the Challenge object in another message and adds its Integrity object to the message to generate a Response message to be sent to node B.

4.When node B receives the Response message from node A, node B checks whether the Challenge object in the Response message is consistent with the local Challenge object or not before performed either of the following operations:

• If the Challenge objects are consistent, node B resets the timer for sending Challenge messages and authentication is successful.
• If the Challenge message timer expires before node B receives the Response message, authentication fails.
  The mpls rsvp-te challenge-lost command is used to change the maximum number of resent Challenge messages. In addition, the mpls rsvp-te retrans-timer challenge command is used to change the interval at which a Challenge message is resent.