Which three NTP operating modes must the trusted-Key command be configured on for authentication to
operate properly? (Choose Three)
Correct Answer: BCE
‘B’ because : “In some contexts, this would be described as a poll operation, in that the client polls the time and authentication data from the server. A client is configured in client mode by using the server command and specifying the domain name server (DNS) name or address.”
‘C’ because : Since an intruder can impersonate a symmetric active peer and inject false time values,
symmetric mode should always be authenticated”.
‘E’ because : Since an intruder can impersonate a broadcast server and inject false time values, this mode
should always be authenticated”.