Which statement about MPLS LDP router ID is true?
Which statement about MPLS LDP router ID is true?
The loopback with the highest IP address is selected as the router ID. This method is used to ensure that the most stable interface (typically a loopback) is used as the LDP router ID, providing consistent reachability and avoiding changes due to dynamic conditions on physical interfaces.
B "LDP will use the router ID as the source of TCP session. These IP has to be /32 and be in reachable. To modify the router ID use the command mpls ldp router-id (inteface) [force]. By default router ID is selected with the highest IP of a loopback, if non exist the highest IP of any active interfaces."
The given answer is correct - The loopback with the highest IP address is selected as the router ID.
https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/mp_ldp/configuration/12-4m/mp-ldp-12-4m-book.pdf
B is correct
B is the correct one, also D could be correct but read the last few words... Is saying without causing any impact :) Cause the router ID of LDP will be also the transport adress then if we change the router id we will tear down the LDP session with our LDP peers, so we need to wait and build UP again the LDP session. If the LDP session is down you can no longer advertise the prefixes in mpls with labels so yeah.... There will be a little impact.
Transport address is the same as the LDP router ID. hold-interval is always set to three times the LDP discovery hello-interval. Transport address is the address used for the TCP session over which LDP is running. If the transport address is not configured, the LDP router-id is used as transport address.
Given answer is correct. As for the "force" keyword: The force keyword forces the LDP router ID to change immediately to the specified address without waiting for a restart of the LDP process. This can cause LDP session flaps and potentially disrupt MPLS LDP label bindings temporarily as the LDP sessions need to be re-established with the new router ID.
the anwser corret is B
The given answer is correct
b win this question.