Cisco Nexus 5600 Series - Configuring NTP Access Restrictions

PurposeCommand or Action
(Optional)
Displays the configured NTP trusted keys.
switch(config)# show ntp
trusted-keys
Step 5
Enables or disables the NTP authentication feature. NTP
authentication is disabled by default.
switch(config)# [no] ntp
authenticate
Step 6
(Optional)
Displays the status of NTP authentication.
switch(config)# show ntp
authentication-status
Step 7
(Optional)
Saves the change persistently through reboots and restarts
by copying the running configuration to the startup
configuration.
switch(config)# copy
running-config startup-config
Step 8
This example shows how to configure the device to synchronize only to time sources that provide authentication
key 42 in their NTP packets:
switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
switch(config)# ntp authentication-key 42 md5 aNiceKey
switch(config)# ntp server 10.1.1.1 key 42
switch(config)# ntp trusted-key 42
switch(config)# ntp authenticate
switch(config)# copy running-config startup-config
[########################################] 100%
switch(config)#
Configuring NTP Access Restrictions
You can control access to NTP services by using access groups. Specifically, you can specify the types of
requests that the device allows and the servers from which it accepts responses.
If you do not configure any access groups, NTP access is granted to all devices. If you configure any access
groups, NTP access is granted only to the remote device whose source IP address passes the access list criteria.
Procedure
PurposeCommand or Action
Enters global configuration mode.switch# configure terminal
Step 1
Creates or removes an access group to control NTP access and
applies a basic IP access list.
switch(config)# [no] ntp
access-group {peer | serve |
Step 2
serve-only | query-only}
access-list-name
The access group options are scanned in the following order, from
least restrictive to most restrictive. However, if NTP matches a deny
ACL rule in a configured peer, ACL processing stops and does not
continue to the next access group option.
•
The peer keyword enables the device to receive time requests
and NTP control queries and to synchronize itself to the servers
specified in the access list.
Cisco Nexus 5600 Series NX-OS System Management Configuration Guide, Release 7.x
226 OL-31641-01
Configuring NTP
Configuring NTP Access Restrictions