Gigamon GigaVUE-HC3, Hardware Installation Manual

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108 GigaVUE-HC3 Hardware Installation Guide
The show ntp will show the current state of the NTP server in use; the show clock
command shows the current GigaVUE H Series node’s time.
Performing One-Time NTP Server Synchronization
You can perform a one-time synchronization with an NTP server using the ntpdate
command. For example:
(config) # ntpdate time.nist.gov
N
OTE
:
This method does not provide updates to correct clock drift over time. It is
generally preferable to use persistent NTP synchronization with the ntp commands.
Using NTP Time Server for Clock Synchronization
The GigaVUE H Series node can optionally use one or more NTP servers for its time
setting. Use the following procedure to add an NTP server to the GigaVUE H Series
node’s list and enable the use of NTP.
1.
Specify the address of the time server. For example, if the time server is on
192.168.1.10, you would use the following command:
(config) # ntp server 192.168.1.10
N
OTE
:
There are many public NTP servers available on the Internet.
2.
Turn on NTP with the following command:
(config) # ntp enable
3.
The GigaVUE H Series node connects to the specified NTP server and
synchronizes to its time.
4.
NTP reports times in UTC. Because of this, it is a good idea to specify the GigaVUE
H Series node’s timezone so that UTC can be converted to the local timezone.
You specify the timezone either in terms of the offset from UTC (either plus or
minus) or with a particular location’s name, depending on the argument you choose
for the
clock timezone command:
• Offset from UTC – Set the timezone as an offset from UTC with the
UTC-offset argument. For example, the following command sets the timezone
as eight hours earlier than UTC:
(config) # clock UTC-offset UTC-8
•
Location – You can specify a particular location’s timezone to use. The easiest
way to do this is to build the available list of cities by adding a space and a
question mark after each subsequent zone word. For example, enter
(config) #
clock timezone ? to see the list of available locations. Select a location and
use the same question mark technique to see the next available zone words.
This way, you can build out to the exact location you need. For example:
(config) # clock timezone America North United_States Pacific
(config) # clock timezone Asia Eastern Hong_Kong
Once you have finished configuring NTP options, use the show ntp command to check
the status of clock synchronization ( Figure 4-27 ).