Cisco Catalyst 9200 Configuration Manual page 32

Configuring NTP Authentication
Command or Action
Step 6
[no] ntp authentication-key number {md5 | cmac-aes-128
| hmac-sha1 | hmac-sha2-256} value
Example:
Device(config)# ntp authentication-key 42 md5
aNiceKey
Step 7 [no] ntp trusted-key key-number
Example:
Device(config)# ntp trusted-key 42
Step 8 [no] ntp server ip-address key key-id [prefer]
Example:
Device(config)# ntp server 172.16.22.44 key 42
System Management Configuration Guide, Cisco IOS XE Gibraltar 16.10.x (Catalyst 9200 Switches)
18
Purpose
• 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 the authentication keys.
• Each key has a key number, a type, and a value.
• Keys can be one of the following types:
• md5: Authentication using the MD5 algorithm.
• 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.
Use the no form of this command to disable trusted
authentication.
Allows the software clock to be synchronized by an NTP
time server.
• ip-address: The IP address of the time server providing
the clock synchronization.
• key-id: Authentication key defined with the ntp
authentication-key command.
Administering the Device