Microsemi SyncServer S200, User Manual

Page: 38 / 190

Web Interface
n
Typical Usage: Broadcast associations to reduce network traffic with a large num-
ber of NTP clients.
n
Broadcast Client:
n
Addressing: The user does not specify an address with this setting.
n
Description: Creates an association that listens for NTP broadcast messages on
all of the network interfaces. Upon receiving the first broadcast message, the
broadcast client association initiates a brief exchange with the server to calibrate
the propagation delay. Afterwards, the broadcast client association listens to and
gets the time from the broadcast server messages. This type of association
requires
authentication on both the server and the clients . See Using NTP
Authentication.
n
Typical Usage: Broadcast client associations can get authenticated time on net-
works that have a broadcast server.
n
Multicast Server: Create a Broadcast association with members of a multicast group.
The multicast address is a class D address starting from 224.0.0.1. (The IANA assigned
224.0.1.1 to be the NTP multicast address.) However, user can choose any class D
address that is not used on the local network by other protocols. Routers can be con-
figured to transmit multicast messages to adjacent subnets.
n
Multicast Client:
n
Addressing: Use the same IPv4 class D multicast address as the Multicast Server
(potentially 224.0.1.1).
n
Description: Creates an association that listens for NTP multicast messages on all
of the network interfaces. Upon receiving the first message, the multicast client
association initiates a brief exchange with the server to calibrate the propagation
delay. Afterwards, the multicast client association listens to and gets the time from
the server messages. This type of association requires
authentication on both the
server and the clients . See Using NTP Authentication.
n
Typical Usage: Multicast client associations can get authenticated time on net-
works that have a multicast server.
Note: When authentication is configured, the same authentication scheme is available for all
NTP associations and over all network interfaces.
Address: The IP address or DNS name of the NTP association.
Burst
n
Burst: When the server is reachable, send a burst of eight packets instead of the usual
one. The packet spacing is about two seconds. This is designed to improve timekeeping
quality for server associations. This setting should only be used in agreement with the
administrator of the remote NTP device as the traffic load may be onerous.
n
iBurst: When the server is unreachable, send a burst of eight packets instead of the usual
one. As long as the server is unreachable, the packet spacing is about 16s. Once the
server is reachable, the packet spacing is about two seconds. This is designed to speed
the initial synchronization acquisition with the
server
command.
Version: Specifies the version number to be used for outgoing NTP packets. Versions 1-4 are
the choices, with version 4 the default.
Page 38 .......................................................................... 997-01520-02 Rev. G2