Setup Guide
Disabling NTP on an Interface
By default, NTP is enabled on all active interfaces. If you disable NTP on an interface, Dell EMC Networking OS drops any NTP packets
sent to that interface.
To disable NTP on an interface, use the following command.
• Disable NTP on the interface.
INTERFACE mode
ntp disable
To view whether NTP is congured on the interface, use the show config command in INTERFACE mode. If ntp disable is not
listed in the show config command output, NTP is enabled. (The show config command displays only non-default conguration
information.)
Conguring a Source IP Address for NTP Packets
By default, the source address of NTP packets is the IP address of the interface used to reach the network.
You can congure one interface’s IP address include in all NTP packets.
To congure an IP address as the source address of NTP packets, use the following command.
• Congure a source IP address for NTP packets.
CONFIGURATION mode
ntp source interface
Enter the following keywords and slot/port or number information:
– For a 1-GigabitEthernet interface, enter the keyword GigabitEthernet then the slot/port information.
– For a 10-Gigabit Ethernet interface, enter the keyword TenGigabitEthernet then the slot/port information.
– 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 conguration, use the show running-config ntp command in EXEC privilege mode (refer to the example in Conguring
NTP Authentication).
Conguring 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 rst NTP packet is created following the conguration 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
dierent from previous Dell EMC Networking OS versions; Dell EMC Networking OS uses data encryption standard (DES) encryption to
store the key in the startup-cong when you enter the ntp authentication-key command. Therefore, if your system boots with a
startup-conguration from an Dell EMC Networking OS version in which you have congured 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-
cong to the startup-cong.
System Time and Date
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