With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
ntpServerPublicKey
ntp Server Public Key
1.3.6.1.4.1.9.5.1.15.4.1.3
server. A key with a value of zero indicates an invalid ntpServerPublicKey. When the authentication feature is enabled the system will not sync with this server when ntpAuthenticationPublicKey doesn't match with NTP Packet's public key. or If the ntpAuthenticationTrustedMode is trusted but encrypted message of ntpAuthenticationSecretKey with NTP packet's data doesn't match with NTP packet's crypto checksum in the message authentication mode (MAC). or If the ntpAuthenticationTrustedMode is untrusted. In client mode NMP will not send request NTP Packet to the server when ntpServerPublicKey doesn't match with any of the ntpAuthenticationPublicKey in ntpAuthenticationTable. or If the ntpAuthenticationTrustedMode is untrusted.
Back to CISCO-STACK-MIB MIB page.
IPHost Network monitor allows you to monitor ntpServerPublicKey on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco routers right now.