Ntp Default Configuration; Configuring Ntp - Cisco WS-X6066-SLB-APC - Content Switching Module Software Manual

NTP Default Configuration

The communications between machines running NTP, known as associations, are usually statically
configured; each machine is given the IP address of all machines with which it should form associations.
Accurate timekeeping is possible by exchanging NTP messages between each pair of machines with an
association. However, in a LAN environment, you can configure NTP to use IP broadcast messages.
With this alternative, you can configure the machine to send or receive broadcast messages, but the
accuracy of timekeeping is marginally reduced because the information flow is one-way only.
Cisco's implementation of NTP does not support stratum 1 service; it is not possible to connect to a radio
or atomic clock. We recommend that you obtain the time service for your network from the public NTP
servers available in the IP Internet. If the network is isolated from the Internet, Cisco's NTP
implementation allows a machine to be configured so that it acts as though it is synchronized using NTP,
when in fact it has determined the time using other means. Other machines then synchronize to that
machine using NTP.
A number of manufacturers include NTP software for their host systems, and a publicly available version
for systems running UNIX and its various derivatives is also available. This software allows
time-synchronized host systems.
NTP Default Configuration
Table 31-1
Table 31-1 NTP Default Configuration
Feature
Broadcast client mode
Client mode
Broadcast delay
Time zone
Offset from UTC
Summertime adjustment
NTP server
Authentication mode

Configuring NTP

These sections describe how to configure NTP:
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Catalyst 6000 Family Software Configuration Guide—Releases 6.3 and 6.4
31-2
shows the default NTP configuration.
Enabling NTP in Broadcast-Client Mode, page 31-3
Configuring NTP in Client Mode, page 31-3
Configuring Authentication in Client Mode, page 31-4
Setting the Time Zone, page 31-5
Enabling the Daylight Saving Time Adjustment, page 31-5
Disabling the Daylight Saving Time Adjustment, page 31-7
Clearing the Time Zone, page 31-7
Chapter 31
Default Value
Disabled
Disabled
3000 microseconds
Not specified
0 hours
Disabled
None specified
Disabled
Configuring NTP
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