Configuring Ntp Authentication - Dell S4048–ON Configuration Manual

• Configure a source IP address for NTP packets.
CONFIGURATION mode
ntp source interface
Enter the following keywords and slot/port or number information:
– For a 10-Gigabit Ethernet interface, enter the keyword TenGigabitEthernet then the slot/port[/subport] information.
– For a 40-Gigabit Ethernet interface, enter the keyword fortyGigE then the slot/port information.
– For a Loopback interface, enter the keyword loopback then a number from 0 to 16383.
– 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
Networking OS uses the message digest 5 (MD5) algorithm and the key is embedded in the synchronization packet that is sent to
an NTP time source.
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
868
System Time and Date