Masterclock NTD200 Series User Manual – v1 – January 2014
17
BROADCAST
NTPS clocks and devices also support the broadcasting of NTP
packets. The broadcast mode is a widespread or open-ended
broadcast, not intended for any specific IP address. Broadcast
packets are useful in situations where network administrators
may wish to avoid heavy network traffic created by periodic NTP
requests. Often such periodic requests end up synchronized,
which can exceed the time server’s ability to reply promptly.
The network device listens for NTP using the
UDP (User Datagram Protocol)
broadcasts using
the broadcast address “255.255.255.255”.
“SOFT” RESTARTS
A soft restart may periodically be performed by the network
device to automatically attempt to rectify a problem it may be
experiencing.
The network device will perform a soft restart under the
following conditions:
1.
If the device is not receiving an NTP poll response or an NTP
broadcast response depending on which mode the NTD200
is in.
2.
If the NTD200 device is set to use DHCP and no DHCP server
can be found.
The timeout before doing a soft restart is not less than ten
minutes.
Note:
Several factors can increase the time between these soft
restarts.
1.
The soft restart will be delayed by two hours if a connection
is made by Telnet or WinDiscovery.
2.
The soft restart could be delayed if the user changes the
default parameters for NTP poll retries/timeouts or the NTP
broadcast times out. For example, if the NTP broadcast
timeout is increased to 60 minutes the soft restart timeout
will also be increased to 60 minutes.
Special Error Indicator
In addition to the standard status
indications, the network clock will
display a special error indicator under
the status window if either a DHCP
server cannot be located, or if the
device has an IP address conflict due to
either DHCP or Static IP addressing.
Under these conditions the unit will
also be assigned a fallback IP address of
“169.254.xxx.xxx”, and appear in
RED
text
under the main “
WinDiscovery
”
window. To determine the cause of
why the clock received a
“169.254.xxx.xxx” address the user
should display the status of the clock.
Near the bottom of the “
Status
”
window the error will be displayed.
