Configures a Network
TIme Protocol (NTP) server for use by the local NTP client in synchronizing
the system clock.
Privilege:
Security Administrator,
Administrator
Syntax
server ip_address [ prefer ] [ version number ] [ minpoll poll_period ] [ maxpoll poll_period ]
no server ip_address
no
Indicates the server
specified is to be removed from the list of NTP servers for clock synchronization.
ip_address
Specifies the IP address
of the NTP server to be used for clock synchronization in IPv4 dotted-decimal
or IPv6 colon-separated-hexadecimal notation.
NTP should be configured
for at least 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).
prefer
Indicates the NTP server
specified to be the preferred server. Only one server can be set
to preferred. The preferred server is the first one contacted for
clock synchronization.
IMPORTANT:
Use of the prefer keyword
is not recommended.
IMPORTANT:
Do not change the version, minpoll or maxpoll keyword
settings unless instructed to do so by Cisco TAC.
version number
Specifies the network
timing protocol version to use for server communications as an integer from
1 to 4. Default: 4 (RFC 5905)
minpoll poll_period
Specifies the minimum
polling interval (in seconds) for NTP messages as a power of 2. poll_period is
the exponent (power of) expressed as an integer from 6 through 17.
For example, if you specify the number 6, the value is 2^6
and the resultant poll period is 64 seconds. Default: 6
maxpoll poll_period
Specifies the maximum
polling interval (in seconds) for NTP messages as a power of 2. poll_period is
the exponent (power of) expressed as an integer from 6 through 17.
For example, if you specify the number 10, the value is 2^10
and the resultant poll period is 1024 seconds. Default: 10
Usage:
Configure the NTP servers
in response to network changes.
Refer to the System Administration
Guide for important information on configuring NTP servers with
local sources, and using a load balancer to communicate with external
NTP servers.
IMPORTANT:
Adding, removing, or
modifying an NTP server configuration entry causes the NTP client
to restart itself and resynchronize with all configured NTP servers.
Example:
The following command
adds the NTP server with address
10.2.3.4 to
the list of NTP servers.
server 10.2.3.4