Dell S4820T Configuration Manual page 957

Dell Networking OS Behavior: Dell Networking OS uses an encryption algorithm to store the
authentication key that is different from previous Dell Networking OS versions; Dell Networking OS uses
data encryption standard (DES) encryption to store the key in the startup-config when you enter the ntp
authentication-key command. Therefore, if your system boots with a startup-configuration from an
Dell Networking OS version in which you have configured ntp authentication-key, the system
cannot correctly decrypt the key and cannot authenticate the NTP packets. In this case, re-enter this
command and save the running-config to the startup-config.
To configure NTP authentication, use the following commands.
1. Enable NTP authentication.
CONFIGURATION mode
ntp authenticate
2. Set an authentication key.
CONFIGURATION mode
ntp authentication-key number md5 key
Configure the following parameters:
• number: the range is from 1 to 4294967295. This number must be the same as the number in the
ntp trusted-key command.
• key: enter a text string. This text string is encrypted.
3. Define a trusted key.
CONFIGURATION mode
ntp trusted-key number
Configure a number from 1 to 4294967295.
The number must be the same as the number used in the ntp authentication-key command.
4. Configure an NTP server.
CONFIGURATION mode
ntp server [vrf] <vrf-name> {hostname | ipv4-address |ipv6-address} [ key
keyid] [prefer] [version number]
Configure the IP address of a server and the following optional parameters:
• – vrf-name : Enter the name of the VRF through which the NTP server is reachable.
– hostname : Enter the keyword hostname to see the IP address or host name of the remote
device.
– ipv4-address : Enter an IPv4 address in dotted decimal format (A.B.C.D).
– ipv6-address : Enter an IPv6 address in the format
0000:0000:0000:0000:0000:0000:0000:0000. Elision of zeros is supported.
– key keyid : Configure a text string as the key exchanged between the NTP server and the
client.
– prefer: Enter the keyword prefer to set this NTP server as the preferred server.
– version number : Enter a number as the NTP version. The range is from 1 to 4.
5. Configure the switch as NTP master.
CONFIGURATION mode
System Time and Date
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