Juniper SYSTEM BASICS - CONFIGURATION GUIDE V 11.1.X Configuration Manual page 561

CAUTION: Be sure that you do not override a valid time source if you specify the
stratum of the NTP server. Issuing the ntp master command on multiple systems in
the network might lead to unreliable timestamps if those systems do not agree on
the time.
3.
ntp broadcast
ntp master
CAUTION: Although you can specify a stratum number of 1, the system does not
support stratum 1 service. The system can synchronize only with an NTP server, and
not directly with an atomic clock or radio clock.
ntp server enable
(Optional) Specify the stratum of this NTP server.
Use to enable broadcast server on an interface to send NTP broadcast messages
periodically.
The server sends the NTP broadcast messages to the local network broadcast
address (255.255.255.255).
Example In this example, the interface supports NTP software, version 4, and
a poll interval of 5 (32 seconds) for broadcasting NTP messages.
host1:boston(config-if)#ntp broadcast version 4 5
Use the no version to prevent the interface from sending NTP broadcast
messages.
See ntp broadcast.
Use to specify the stratum number of a virtual router you configured as an NTP
server
By default, the stratum number is set to the stratum number of the master plus
one.
Specify a stratum number for the system in the range 1 – 15. A stratum n server
is n hops from an accurate time source.
Example
host1:boston(config)#ntp master
Use the no version to restore the default stratum number.
See ntp master.
Use to enable a virtual router to act as an NTP server.
Example
Chapter 10: Configuring the System Clock
NTP Configuration Tasks
531