Users Guide

● Configure a source IP address for NTP packets in CONFIGURATION mode.
ntp source interface
○ ethernet node/slot/port[:subport]—Enter the Ethernet interface information.
○ port-channel channel-id—Enter the port-channel ID, from 1 to 128.
○ vlan vlan-id—Enter the VLAN ID number, from 1 to 4093.
○ loopback id—Enter the Loopback interface ID number, from 0 to 16383.
○ mgmt node/slot/port—Enter the physical port interface for the Management interface. The default is 1/1/1.
Configure the source IP address
OS10(config)# ntp source ethernet 1/1/10
View the source IP configuration
OS10(config)# do show running-configuration | grep source
ntp source ethernet1/1/1
Authentication
NTP authentication and the corresponding trusted key provide a reliable exchange of NTP packets with trusted time sources.
NTP authentication begins with creating the first NTP packet after the key configuration. NTP authentication uses the message
digest 5 (MD5), SHA-1, and SHA2-256 algorithms. The key is embedded in the synchronization packet that is sent to an NTP
time source.
1. Enable NTP authentication in CONFIGURATION mode.
ntp authenticate
2. Set an authentication key number and key in CONFIGURATION mode, from 1 to 65535.
ntp authentication-key number hash-algorithm {0|9} key
● The number must match in the ntp trusted-key command.
● The supported hash-algorithms include md5, sha1, and sha2-256.
● The 0 specifies an unencrypted authentication key and 1 specifies an encrypted authentication key.
● The key is an encrypted string.
3. Define a trusted key in CONFIGURATION mode, from 1 to 65535. This number must match the configured NTP
authentication key.
ntp trusted-key number
4. Configure an NTP server in CONFIGURATION mode.
ntp server {hostname | ipv4-address | ipv6-address} [key keyid] [prefer]
● hostname—Enter the keyword to see the IP address or hostname of the remote device.
● ipv4-address—Enter an IPv4 address in A.B.C.D format.
● ipv6-address—Enter an IPv6 address in nnnn:nnnn:nnnn:nnnn:nnnn:nnnn:nnnn:nnnn format. Elision of zeros is
supported.
● key keyid—Enter a text string as the key exchanged between the NTP server and the client.
● prefer—Enter the keyword to set this NTP server as the preferred server.
5. Configure the NTP master and enter the stratum number that identifies the NTP server hierarchy in CONFIGURATION
mode, from 2 to 10. The default is 8.
The ntp master command enables the local switch to serve time to other client devices when the configured real-time
sources are not reachable.
ntp master {2–10}
System management
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