Which statement about BGP Update messages is false?

BGP (Border Gateway Protocol) Update messages are a fundamental aspect of how routing information is exchanged between BGP peers. The statement that these messages are sent in multicast mode is false. BGP is designed to operate using TCP, which inherently relies on unicast communication between the peers. This means that each BGP Update message is sent directly to a single specific peer rather than to multiple peers simultaneously as would be the case with multicast.

In contrast, the other statements about BGP Update messages are accurate. They are typically sent after Keepalive messages to maintain the session between peers, and they serve the function of exchanging routing information—providing updates about available routes. Additionally, BGP Update messages can convey multiple reachable routes in a single message, allowing for efficient communication of routing information across complex networks. Thus, understanding the nature of BGP message transmissions helps clarify the role and mechanics of routing information exchanges in the context of network operations.