Which statement regarding LDP Discovery messages is true?

The statement that the destination IP address is the multicast IP address 224.0.0.2 is true because in the context of LDP (Label Distribution Protocol), LDP Discovery messages are initially sent out to a multicast address. This address, 224.0.0.2, is specifically designated for LDP discovery and is utilized for sending Hello messages among LSRs (Label Switching Routers). These Hello messages facilitate the discovery of LDP neighbors within a network segment, allowing LSRs to dynamically find and establish connections with one another.

The selection of 224.0.0.2 as a multicast address is particularly effective in a network environment because it enables multiple LSRs to receive the discovery messages simultaneously, reducing the overhead of managing individual peer connections in the initial stages of establishing LDP sessions. This multicast approach aids in the quick and efficient discovery of all routers that are configured to use LDP on the same network segment.

In terms of LDP behavior, once TCP connections are established, LSRs typically switch from sending Hello messages to using the established connection to exchange label information. Therefore, while there may be instances where Hello messages are still sent during the lifetime of the connection for keepalive purposes, it is