Synchronizing The Ace With An Ntp Server - Cisco 4700M Administration Manual

Setting Up the ACE
Command
no clock summer-time
Example:
host1/Admin(config)# no clock summer-time
Step 3
do copy running-config startup-config
Example:
host1/Admin(config)# do copy
running-config startup-config

Synchronizing the ACE with an NTP Server

This section describes how to use Network Time Protocol (NTP) to synchronize the ACE system clock
to a time server. NTP is an Internet protocol designed to synchronize the clocks of computers over a
network. Typically, an NTP network receives its time from an authoritative time source, such as a radio
clock or an atomic clock attached to a time server, and assures accurate local time-keeping. NTP
distributes this time across the network. The NTP protocol can synchronize distributed clocks within
milliseconds over long time periods.
NTP runs over User Datagram Protocol (UDP), which runs over IP. NTP is documented in RFC 1305.
All NTP communication uses Coordinated Universal Time (UTC), which is the same as Greenwich
Mean Time.
An NTP association can be a peer association, which means that the ACE is willing to synchronize to
the other system or to allow the other system to synchronize to the ACE. An NTP association can also
be a server association, which means that only this system will synchronize to the other system, not the
other way around. You can identify multiple servers; the ACE uses the most accurate server. To configure
the ACE system clock to synchronize a peer (or to be synchronized by a peer) or to be synchronized by
a time server, use the ntp command. To display a list of the current associated peers and NTP statistical
information, see the
Prerequisites
This configuration topic includes the following prerequisites:
•
•
Restrictions
Only users authenticated in the Admin context can use the ntp command.
Cisco 4700 Series Application Control Engine Appliance Administration Guide
1-22
"Displaying NTP Statistics and Information"
An NTP server must be accessible by the client ACE.
If you are configuring application acceleration and optimization functionality (as described in the
Cisco 4700 Series Application Control Engine Appliance Application Acceleration and
Optimization Configuration Guide), and you plan to use an optional Cisco AVS 3180A Management
Console with multiple ACE nodes, we strongly recommend that you synchronize the system clock
of each ACE node with an NTP server. AppScope performance monitoring relies on very accurate
time measurement, in the millisecond range. If you instal multiple ACE appliances, you must
synchronize the clocks so that different parts of a single transaction can be handled by different
nodes.
Purpose
(Optional) Remove the clock summer-time setting.
(Optional) Copies the running configuration to the startup
configuration.
Chapter 1 Setting Up the ACE
section.
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