Validating LDP session reset

• The LDP session state transitions from Operational to Nonexistent upon clearing it. However, the states may quickly transition. In this case, the show mpls ldp session command shows the Up time, and that it was reset to zero upon clearing the session.
• The LDP session specific database is cleaned upon resetting the LDP session.
• The TCP port number on the active end of the LDP session may have been changed once the LDP session comes up after the reset; the TCP port number before and after the reset may be different. Use the show mpls ldp session command to view the TCP port number.
• Syslog logs the event of a LDP session going down and then coming back up as a result of resetting the LDP session. Use the command show log to view the syslog events.

The following command shows two LDP sessions with neighbor 10.234.123.64.

device# show mpls ldp session
 Number of link LDP sessions: 1
 Number of Operational link LDP sessions: 1
 Number of targeted LDP sessions: 0
 Number of Operational targeted LDP sessions: 0
Peer LDP ID              State          Adj Used  My Role   Max Hold  Time Left
10.234.123.64            Operational    Link      Passive   36        33

The following command clears both the link and targeted LDP session with neighbor 10.234.123.64.

device# clear mpls ldp neighbor 10.234.123.64
device#
device# show mpls ldp session
Peer LDP ID              State          My Role   Max Hold  Time Left
10.234.123.64            Operational    Passive   36        33

This command shows that after waiting for roughly 20 seconds (depends on the hello or keepalive timer periodicity), both the LDP sessions are reestablished.

device# show mpls ldp session
Peer LDP ID              State          My Role   Max Hold  Time Left
10.234.123.64            Operational    Passive   36        33