Creating NTP Restrict Entries

Perform the following procedure to configure the NTP restrict capability for a specific IPv4 or IPv6 address(es), which means the switch permits NTP traffic flow from the specified IP addresses only. By default the NTP restrict capability is disabled.

Note

You can configure a maximum of 128 NTP Restrict entries (IPv4 or IPv6 addresses).
0.0.0.0/0 or ::/0 NTP restrict entries are equivalent to no NTP restrict rules configured.

Procedure

Enter Global Configuration mode:

enable

configure terminal
Configure a specific NTP restrict IP address:

ntp restrict WORD<0-255>
Verify the restricted IP address:

show ntp restrict

Example

Switch:1>enable
Switch:1#configure terminal
Switch:1(config)#ntp restrict 192.0.0.0
Switch:1(config)#show ntp restrict
================================================================================
                            NTP Restrict Information
================================================================================
TYPE     ADDRESS                                    MASK/PREFIX LEN
--------------------------------------------------------------------------------
IPv4     192.0.0.0                                    23
--------------------------------------------------------------------------------

Variable Definitions

The following table defines parameters for the ntp restrict command:


Variable	Value
`WORD<0-255>`	Specifies the IPv4 or IPv6 address. Note: You can configure a maximum of 128 IPv4 and IPv6 addresses in the NTP restrict list.