Cisco Systems SMC-169 manual SMC-174

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Implementing NTP on Cisco IOS XR Software

How to Implement NTP on Cisco IOS XR Software

When a networking device is operating in the broadcastclient mode, it does not engage in any polling. Instead, it listens for NTP broadcast packets transmitted by broadcast time servers. Consequently, time accuracy can be marginally reduced, because time information flows only one way.

Use the broadcast client command to set your networking device to listen for NTP broadcast packets propagated through a network. For broadcastclient mode to work, the broadcast server and its clients must be located on the same subnet. The time server that is transmitting NTP broadcast packets must be enabled on the interface of the given device using the broadcast command.

SUMMARY STEPS

1.configure

2.ntp

3.broadcastdelay microseconds

4.interface type instance

5.broadcast client

6.broadcast [destination ip-address] [key key-id] [version number]

7.end or commit

DETAILED STEPS

 

Command or Action

Purpose

Step 1

 

 

configure

Enters global configuration mode.

 

Example:

 

 

RP/0/RP0/CPU0:router# configure

 

Step 2

 

 

ntp

Enters NTP configuration mode.

 

Example:

 

 

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

 

Step 3

 

 

broadcastdelay microseconds

Adjusts the estimated round-trip delay for NTP broadcasts.

 

Example:

 

 

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

 

 

broadcastdelay 5000

 

Step 4

 

 

interface type instance

Enters NTP interface configuration mode.

 

Example:

 

 

RP/0/RP0/CPU0:router(config-ntp)# interface POS

 

 

0/1/0/0

 

Step 5

 

 

broadcast client

Configures the specified interface to receive NTP broadcast

 

 

 

 

packets.

 

Example:

 

 

RP/0/RP0/CPU0:(config-ntp-int)# broadcast

 

 

client

 

 

 

 

 

 

 

 

 

Cisco IOS XR System Management Configuration Guide

 

 

 

 

 

 

 

 

 

 

SMC-174

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Contents Implementing NTP on Cisco IOS XR Software NTP Functional Overview SMC-170Configuring Poll-Based Associations Poll-Based AssociationsSMC-171 Summary Steps SMC-172Configuring Broadcast-Based NTP Associations Broadcast-Based NTP AssociationsSMC-173 SMC-174 Configuring NTP Access Groups NTP Access GroupsSMC-175 SMC-176 SMC-177 Configuring NTP Authentication NTP AuthenticationSMC-178 Supported is md5 SMC-179Disabling NTP Services on a Specific Interface SMC-180SMC-181 Configuring the Source IP Address for NTP Packets SMC-182SMC-183 Configuring the System as an Authoritative NTP Server SMC-184Updating the Hardware Clock SMC-185SMC-186 Verifying the Status of the External Reference Clock ExamplesSMC-187 Configuring Poll-Based Associations Example Configuring Broadcast-Based Associations ExampleSMC-188 Configuring NTP Access Groups Example Configuring NTP Authentication ExampleSMC-189 Configuring the Source IP Address for NTP Packets Example Disabling NTP on an Interface ExampleSMC-190 Standards Updating the Hardware Clock ExampleRelated Documents MIBsRFCs Technical AssistanceSMC-192