Administrator Guide

• For a Loopback interface, enter the keyword loopback then a number from 0 to 16383.
• For the Management interface, enter the keyword ManagementEthernet then the slot/port information.
• For a port channel interface, enter the keywords port-channel then a number.
• For a VLAN interface, enter the keyword vlan then a number from 1 to 4094.
To view the configuration, use the show running-config ntp command in EXEC privilege mode (refer to the example in
Configuring NTP Authentication).
Configuring NTP Authentication
NTP authentication and the corresponding trusted key provide a reliable means of exchanging NTP packets with trusted time sources.
NTP authentication begins when the first NTP packet is created following the configuration of keys. NTP authentication in Dell EMC
Networking OS uses the Message Digest 5 (MD5) or Secure Hash Algorithm 1 (SHA1) algorithm and the key is embedded in the
synchronization packet that is sent to an NTP time source.
Dell EMC Networking OS Behavior: Dell EMC Networking OS uses an encryption algorithm to store the authentication key that is
different from previous Dell EMC Networking OS versions; Dell EMC 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 EMC 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 | sha1} key
Configure the following parameters:
• number: the range is from 1 to 65534. 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 65534.
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][minpoll] [maxpoll]
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.
• minpoll polling-interval: Enter the minpoll value. The range is from 4 to 16.
• maxpoll polling-interval: Enter the maxpoll value. The range is from 4 to 16.
5. Configure the switch as NTP master.
CONFIGURATION mode
ntp master <stratum>
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System Time and Date