Purpose
Command or Action
•
cmac-aes-128
: Authentication using Cipher-based
message authentication codes (CMAC) with the
AES-128 algorithm. The digest length is 128 bits
and the key length is 16 or 32 bytes.
•
hmac-sha1
: Authentication using Hash-based
Message Authentication Code (HMAC) using the
SHA1 hash function. The digest length is 128 bits
and the key length is 1 to 32 bytes.
•
hmac-sha2-256
: Authentication using HMAC
using the SHA2 hash function. The digest length
is 256 bits and the key length is 1 to 32 bytes
Use the
no
form of this command to remove authentication
key.
Defines trusted authentication keys that a peer NTP device
must provide in its NTP packets for this device to
synchronize to it.
[
no
]
ntp trusted-key key-number
Example:
Device(config)#
ntp trusted-key 42
Step 5
Use the
no
form of this command to disable trusted
authentication.
Allows the software clock to be synchronized by an NTP
time server.
[
no
]
ntp server ip-address key key-id
[
prefer
]
Example:
Step 6
•
ip-address
: The IP address of the time server providing
the clock synchronization.
Device(config)#
ntp server 172.16.22.44 key 42
•
key-id
: Authentication key defined with the
ntp
authentication-key
command.
•
prefer
: Sets this peer as the preferred one that provides
synchronization. This keyword reduces clock hop
among peers.
Use the
no
form of this command to remove a server
association.
Returns to privileged EXEC mode.
end
Example:
Step 7
Device(config)#
end
Configuring Poll-Based NTP Associations
To configure poll-based NTP associations, perform this procedure:
System Management Configuration Guide, Cisco IOS XE Fuji 16.8.x (Catalyst 9500 Switches)
16
Administering the Device
Configuring Poll-Based NTP Associations
