Configuring Broadcast-Based NTP Associates
In a broadcast-based NTP association, an NTP server propagates NTP broadcast packets throughout a network.
Broadcast clients listen for the NTP broadcast packets propagated by the NTP server and do not engage in
any polling.
Broadcast-based NTP associations should be used when time accuracy and reliability requirements are modest
and if your network is localized and has a large number of clients (more than 20). Broadcast-based NTP
associations also are recommended for use on networks that have limited bandwidth, system memory, or CPU
resources. Time accuracy is marginally reduced in broadcast-based NTP associations because 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 broadcast client 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.
Use the broadcast command to set your networking device to send NTP broadcast packets.
No specific command enables NTP; the first NTP configuration command that you issue enables NTP.Note
SUMMARY STEPS
1.
configure
2.
ntp
3.
(Optional) broadcastdelay microseconds
4.
interface type interface-path-id
5.
broadcast client
6.
broadcast [destination ip-address] [key key-id] [version number]
7.
Use one of the following commands:
•
end
•
commit
DETAILED STEPS
PurposeCommand or Action
configure
Step 1
Enters NTP configuration mode.ntp
Example:
RP/0/RSP0/CPU0:router(config)# ntp
Step 2
Cisco ASR 9000 Series Aggregation Services Router System Management Configuration Guide, Release 5.1.x
212
Implementing NTP
Configuring Broadcast-Based NTP Associates