•
NTP configured for use in the local context only. Use of other contexts (which can be specified in the
enable configurable) will cause issues.
•
NTP configured for three external NTP servers. With three or more servers, outlyers and broken or
misconfigured servers can be detected and excluded. Generally, the more servers the better (within
reason).
Do not configure any external NTP servers using the
prefer
keyword. The NTP clock selection algorithms
already have the built-in ability to pick the best server. Use of
prefer
usually results in a poorer choice
than NTP can determine for itself.
Important
Do not change the
maxpoll
,
minpoll
, or
version
keyword settings unless instructed to do so by Cisco
TAC.
Important
Basic NTP Configuration
Configure the system clock and time zone prior to implementing NTP support. This greatly simplifies the
time zone shift that must be corrected by the NTP server. See
Setting the System Clock and Time Zone,
on page 109
.
Important
Use the following example to configure the necessary NTP association parameters:
[local]host_name#
config
[local]host_name(config)#
ntp
[local]host_name(config-ntp)#
enable
[local]host_name(config-ntp)#
server ip_address1
[local]host_name(config-ntp)#
server ip_address2
[local]host_name(config-ntp)#
server ip_address3
[local]host_name(config-ntp)#
end
[local]host_name#
By default
context_name
is set to
local
. This is the recommended configuration.
A number of options exist for the
ntp server
command. Refer to the
NTP Configuration Mode Commands
chapter in the
Command Line Interface Reference
for more information.
Configure the system with at least three (preferably four) NTP servers.
Important
Save the configuration as described in
Save the Basic Configuration, on page 112
.
Configuring NTP Servers with Local Sources
NTP can use network peers, local external clocks (such as GPS devices), or a local clock with no external
source.
ASR 5500 Installation Guide
110
Initial System Configuration
Configuring Network Time Protocol Support
Summary of Contents for ASR 5500
Page 12: ...ASR 5500 Installation Guide xii Contents ...
Page 16: ...ASR 5500 Installation Guide xvi About this Guide Contacting Customer Support ...
Page 40: ...ASR 5500 Installation Guide 24 Technical Specifications Chassis Grounding ...
Page 74: ...ASR 5500 Installation Guide 58 Card Installation Save Shipping Cartons ...
Page 88: ...ASR 5500 Installation Guide 72 MIO Port Cabling Cleaning Fiber Optic Connectors ...
Page 112: ...ASR 5500 Installation Guide 96 System Power up show leds Command ...
Page 130: ...ASR 5500 Installation Guide 114 Initial System Configuration Additional Configuration Tasks ...
Page 164: ...ASR 5500 Installation Guide 148 Replaceable Components Returning Failed Components ...
Page 186: ...ASR 5500 Installation Guide 170 Console Port to Cisco Server Cabling Configuration ...
Page 192: ...ASR 5500 Installation Guide 176 RMA Shipping Procedures Rear Cards ...