Cisco Systems SMC-169 manual Configuring NTP Access Groups, SMC-175

Implementing NTP on Cisco IOS XR Software

How to Implement NTP on Cisco IOS XR Software

	Command or Action	Purpose
Step 6
	broadcast [destination ip-address] [key key-id]	Configures the specified interface to send NTP broadcast
	[version number]	packets.
	Example:
	RP/0/RP0/CPU0:(config-ntp-int)# broadcast
	destination 10.50.32.149
Step 7
	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.

Configuring NTP Access Groups

This task explains how to configure NTP access groups.

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

NTP Access Groups

The access list-based restriction scheme allows you to grant or deny certain access privileges to an entire network, a subnet within a network, or a host within a subnet.

The access group options are scanned in the following order, from least restrictive to most restrictive:

1.peer—Allows time requests and NTP control queries and allows the system to synchronize itself to a system whose address passes the access list criteria.

2.serve—Allows time requests and NTP control queries, but does not allow the system to synchronize itself to a system whose address passes the access list criteria.

3.serve-only—Allows only time requests from a system whose address passes the access list criteria.

4.query-only—Allows only NTP control queries from a system whose address passes the access list criteria.

Cisco IOS XR System Management Configuration Guide

SMC-175