Service Manual

• Congure 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-Gigabit Ethernet 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 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 conguration, use the show running-config ntp command in EXEC privilege mode (refer to the example in
Conguring NTP Authentication).
Conguring 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 conguration 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 dierent
from previous Dell Networking OS versions; Dell Networking OS uses data encryption standard (DES) encryption to store the key in
the startup-cong when you enter the ntp authentication-key command. Therefore, if your system boots with a startup-
conguration from an Dell Networking OS version in which you have congured
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-
cong to the startup-cong.
To congure 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
Congure 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. Dene a trusted key.
CONFIGURATION mode
ntp trusted-key number
Congure a number from 1 to 4294967295.
The number must be the same as the number used in the ntp authentication-key command.
4. Congure an NTP server.
CONFIGURATION mode
764
System Time and Date