This document provides a sample configuration for Network Time Protocol
(NTP) version 4 in IPv6 on the Cisco Catalyst 3560 Series Switch.
Make sure that you meet these requirements before you attempt this
Have basic knowledge of configuration on Cisco Catalyst 3560 Series
Have basic knowledge of NTP version 4
Have basic knowledge of IPv6
The information in this document is based on the Cisco Catalyst 3560
The information in this document was created from the devices in a
specific lab environment. All of the devices used in this document started with
a cleared (default) configuration. If your network is live, make sure that you
understand the potential impact of any command.
Refer to the
Technical Tips Conventions for more information on document
The NTP is designed to time-synchronize a network of devices. NTP runs
over User Datagram Protocol (UDP), which runs over IP.
An NTP network typically gets its time from an authoritative time
source, such as a radio clock or an atomic clock attached to a time server. NTP
then distributes this time across the network. Cisco recommends that the time
service for your network be derived from the public NTP servers available on
the IP Internet. Use the security features of NTP in order to avoid the
accidental or malicious setting of an incorrect time.
NTP Version 4 (NTPv4) is an extension of NTP version 3. NTPv4 supports
both IPv4 and IPv6 and is backward compatible with NTPv3.
The association between devices running NTP are known. Each device is
given the IP address of all devices with which it should form associations.
Accurate timekeeping is possible by exchanging NTP messages between each pair
of devices with an association.
In this section, you are presented with the information to configure
the NTPv4 in IPv6 described in this document.
Note: Use the
Command Lookup Tool
(registered customers only)
to obtain more information on
the commands used in this section.
This document uses this network setup:
This document uses these configurations:
Catalyst 3560 Switch
!--- Allow the software clock to be synchronized by an NTP time server.
Switch_3560(config)#ntp server 2001:DB8:0:0:8:800:200C:417A version 4
!--- Configure the device to send NTPv4 multicast packets on a specified
Switch_3560(config-if)#ntp multicast FF02::1:FF0E:8C6C
!--- Configure the device to receive NTP multicast packets on a specified
Switch_3560(config-if)#ntp multicast client FF02::1:FF0E:8C6C
!--- Configure NTPv4 authentication.
!--- Define an authentication key.
Switch_3560(config)#ntp authentication-key 30 md5 keyname
!--- Authenticate the identity of a system to which NTPv4 will synchronize.
Switch_3560(config)#ntp trusted-key 30
!--- Configure the source address in NTPv4 packet.
Switch_3560(config)#ntp source FastEthernet 0/1
!--- Periodically update the calendar from NTPv4 time source.
!--- Save the configurations in the device.
Switch_3560(config)#copy running-config startup-config
Use this section in order to confirm that your configuration works
Output Interpreter Tool
(registered customers only)
(OIT) supports certain
show commands. Use the OIT to view an analysis of
show command output.
command in order to view the time and date from the
system software clock.
command in order to view the status of
command in order to view the status of the
There is currently no specific troubleshooting information available
for this configuration.