Configuring Ntp Authentication - Cisco Nexus 5600 Series Configuration Manual

Configuring NTP
Step 4
Step 5

Configuring NTP Authentication

You can configure the device to authenticate the time sources to which the local clock is synchronized. When
you enable NTP authentication, the device synchronizes to a time source only if the source carries one of the
authentication keys specified by the ntp trusted-key command. The device drops any packets that fail the
authentication check and prevents them from updating the local clock. NTP authentication is disabled by
default.
Before You Begin
Authentication for NTP servers and NTP peers is configured on a per-association basis using the key keyword
on each ntp server and ntp peer command. Make sure that you configured all NTP server and peer associations
with the authentication keys that you plan to specify in this procedure. Any ntp server or ntp peer commands
that do not specify the key keyword will continue to operate without authentication.
Procedure
Step 1
Step 2
Step 3
Step 4
OL-31641-01
Command or Action
switch(config)# show ntp
peers
switch(config)# copy
running-config startup-config
Command or Action
switch# configure terminal
switch(config)# [no] ntp
authentication-key number md5
md5-string
switch(config)# show ntp
authentication-keys
switch(config)# [no] ntp
trusted-key number
Cisco Nexus 5600 Series NX-OS System Management Configuration Guide, Release 7.x
Purpose
(Optional)
Displays the configured server and peers.
Note A domain name is resolved only when you have a DNS
server configured.
(Optional)
Saves the change persistently through reboots and restarts by copying
the running configuration to the startup configuration.
Purpose
Enters global configuration mode.
Defines the authentication keys. The device does not
synchronize to a time source unless the source has one of
these authentication keys and the key number is specified
by the ntp trusted-key number command.
(Optional)
Displays the configured NTP authentication keys.
Specifies one or more keys (defined in Step 2) that a time
source must provide in its NTP packets in order for the
device to synchronize to it. The range for trusted keys is
from 1 to 65535.
This command provides protection against accidentally
synchronizing the device to a time source that is not
trusted.
Configuring NTP Authentication
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