Regarding BGP configuration authentication, which is true?

The correct statement regarding BGP (Border Gateway Protocol) configuration authentication is that a pair of BGP peers must use the same MD5 password. BGP uses MD5 (Message-Digest Algorithm 5) to ensure that the information exchanged between BGP peers is authenticated and protected from unauthorized access or tampering.

When configured, both peers will include the MD5 hash of the shared password in the BGP messages they send to each other. Only if the MD5 password matches will the peers accept the BGP message, ensuring both connections are secure and verified. Using MD5 helps in maintaining the integrity of the session and prevents any malicious attempts to disrupt or hijack the BGP routing process.

Other options that suggest all routers in the same AS must use the same password, or that all BGP peers of a router must use the same password, are not accurate. The authentication configuration can vary between different pairs of peers; thus, each pair can have distinct passwords as long as they match only for that specific peer connection.