25-23Before Switch B can synchronize its clock to that of Switch A, you need to enable NTP authenticationfor Switch A.Perform the following configuration on Switch A:# Enable NTP authentication.[SwitchA] ntp-service authentication enable# Set an authentication key.[SwitchA] ntp-service authentication-keyid 42 authentication-mode md5 aNiceKey# Specify the key as a trusted key.[SwitchA] ntp-service reliable authentication-keyid 42# View the NTP status of Switch B after clock synchronization.[SwitchB] display ntp-service statusClock status: synchronizedClock stratum: 3Reference clock ID: 1.0.1.11Nominal frequency: 64.0000 HzActual frequency: 64.0000 HzClock precision: 2^7Clock offset: 0.0000 msRoot delay: 31.00 msRoot dispersion: 1.05 msPeer dispersion: 7.81 msReference time: 14:53:27.371 UTC Sep 19 2005 (C6D94F67.5EF9DB22)As shown above, Switch B has been synchronized to Switch A, and the clock stratum level of Switch Bis 3, while that of Switch A is 2.# View the NTP session information of Switch B, which shows that an association has been set upSwitch B and Switch A.[SwitchB] display ntp-service sessionssource reference stra reach poll now offset delay disper**************************************************************************[12345] 1.0.1.11 127.127.1.0 2 63 64 3 -75.5 31.0 16.5note: 1 source(master),2 source(peer),3 selected,4 candidate,5 configuredTotal associations : 1Configuring NTP Broadcast Mode with AuthenticationNetwork requirementsz The local clock of Switch C is to be used as the master clock, with a stratum level of 3.
