CLI Reference Guide-R04

Chapter 4 | System Management Commands
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Command Usage
You can enable NTP authentication to ensure that reliable updates are received
from only authorized NTP servers. The authentication keys and their associated key
number must be centrally managed and manually distributed to NTP servers and
clients. The key numbers and key values must match on both the server and client.
Example
Console(config)#ntp authenticate
Console(config)#
Related Commands
ntp authentication-key (166)
ntp
authentication-key
This command configures authentication keys and key numbers to use when NTP
authentication is enabled. Use the no form of the command to clear a specific
authentication key or all keys from the current list.
Syntax
ntp authentication-key number md5 key
no ntp authentication-key [number]
number - The NTP authentication key ID number. (Range: 1-65535)
md5 - Specifies that authentication is provided by using the message
digest algorithm 5.
key - An MD5 authentication key string. The key string can be up to 32 case-
sensitive printable ASCII characters (no spaces).
Default Setting
None
Command Mode
Global Configuration
Command Usage
◆ The key number specifies a key value in the NTP authentication key list. Up to
255 keys can be configured on the switch. Re-enter this command for each
server you want to configure.
◆ Note that NTP authentication key numbers and values must match on both the
server and client.
◆ NTP authentication is optional. When enabled with the ntp authenticate
command, you must also configure at least one key number using this
command.