The value of tmnxNtpServersAuthKeyId specifies the key-id of
the authentication key and its authentication type used by this
node to receive and transmit NTP packets to and from
an NTP node. When an NTP packet is received by this node
both authentication key and authentication type must be valid
otherwise the packet will be rejected and an tmnxNtpAuthMismatch
notification generated. When the value of tmnxNtpServersAuthKeyId
has a value of '0', no authentication is performed.