Cisco Systems SMC-169 manual Updating the Hardware Clock, SMC-185

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Implementing NTP on Cisco IOS XR Software

How to Implement NTP on Cisco IOS XR Software

 

Command or Action

Purpose

Step 3

 

 

master stratum

Makes the router an authoritative NTP server.

 

 

Note Use the master command with caution. It is very

 

Example:

easy to override valid time sources using this

 

RP/0/RP0/CPU0:router(config-ntp)# master 9

command, especially if a low stratum number is

 

 

configured. Configuring multiple machines in the

 

 

same network with the master command can cause

 

 

instability in timekeeping if the machines do not

 

 

agree on the time.

Step 4

 

 

end

Saves configuration changes.

 

or

When you issue the end command, the system prompts

 

 

 

commit

you to commit changes:

 

 

Uncommitted changes found, commit them before

 

Example:

exiting(yes/no/cancel)?

 

RP/0/RP0/CPU0:router(config)# end

[cancel]:

 

 

 

or

Entering yes saves configuration changes to the

 

RP/0/RP0/CPU0:router(config)# commit

 

running configuration file, exits the configuration

 

 

session, and returns the router to EXEC mode.

 

 

Entering no exits the configuration session and

 

 

returns the router to EXEC mode without

 

 

committing the configuration changes.

 

 

Entering cancel leaves the router in the current

 

 

configuration session without exiting or

 

 

committing the configuration changes.

 

 

Use the commit command to save the configuration

 

 

changes to the running configuration file and remain

 

 

within the configuration session.

 

 

 

Updating the Hardware Clock

This task explains how to configure the hardware clock to be periodically updated from the software clock running NTP.

On devices that have hardware clocks (system calendars), you can configure the hardware clock to be periodically updated from the software clock. This is advisable for any device using NTP, because the time and date on the software clock (set using NTP) is more accurate than the hardware clock, because the time setting on the hardware clock has the potential to drift slightly over time.

Note No specific command enables NTP; the first NTP configuration command that you issue enables NTP.

Cisco IOS XR System Management Configuration Guide

SMC-185

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Contents Implementing NTP on Cisco IOS XR Software SMC-170 NTP Functional OverviewSMC-171 Configuring Poll-Based AssociationsPoll-Based Associations SMC-172 Summary StepsSMC-173 Configuring Broadcast-Based NTP AssociationsBroadcast-Based NTP Associations SMC-174 SMC-175 Configuring NTP Access GroupsNTP Access Groups SMC-176 SMC-177 SMC-178 Configuring NTP AuthenticationNTP Authentication SMC-179 Supported is md5SMC-180 Disabling NTP Services on a Specific InterfaceSMC-181 SMC-182 Configuring the Source IP Address for NTP PacketsSMC-183 SMC-184 Configuring the System as an Authoritative NTP ServerSMC-185 Updating the Hardware ClockSMC-186 SMC-187 Verifying the Status of the External Reference ClockExamples SMC-188 Configuring Poll-Based Associations ExampleConfiguring Broadcast-Based Associations Example SMC-189 Configuring NTP Access Groups ExampleConfiguring NTP Authentication Example SMC-190 Configuring the Source IP Address for NTP Packets ExampleDisabling NTP on an Interface Example Related Documents Updating the Hardware Clock ExampleStandards MIBsSMC-192 RFCsTechnical Assistance