F3726, F3211, F3174, R5135, R3816-HP Firewalls and UTM Devices System Management and Maintenance Configuration Guide-6PW100

114
Ste
p
Command Remarks
2. Enter interface view.
interface interface-type
interface-number
This command enters the view of
the interface for sending NTP
multicast messages.
3. Configure the device to
operate in NTP multicast
server mode.
ntp-service multicast-server
[ ip-address ]
[ authentication-keyid keyid | ttl
ttl-number | version number ] *
A multicast server can synchronize
broadcast clients only when its
clock has been synchronized.
77B
Configuring the local clock as a reference source
A network device can get its clock synchronized in either of the following two ways:
• Synchronized to the local clock, which operates as the reference source.
• Synchronized to another device on the network in any of the four NTP operation modes previously
described.
If you configure two synchronization modes, the device selects the optimal clock as the reference source.
Typically, the stratum level of the NTP server that is synchronized from an authoritative clock (such as an
atomic clock) is set to 1. This NTP server operates as the primary reference source on the network, and
other devices synchronize to it. The number of NTP hops that devices in a network are away from the
primary reference source determines the stratum levels of the devices.
If you configure the local clock as a reference clock, the local device can act as a reference clock to
synchronize other devices in the network. Perform this configuration with caution to avoid clock errors in
the devices in the network.
To configure the local clock as a reference source:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Configure the local clock as a
reference source.
ntp-service refclock-master
[ ip-address ] [ stratum ]
The value of the ip-address
argument must be 127.127.1.u,
where u ranges from 0 to 3,
representing the NTP process ID.
78B
Configuring optional parameters for NTP
This section explains how to configure the optional parameters of NTP.
240BSpecifying the source interface for NTP messages
If you specify the source interface for NTP messages, the device sets the source IP address of the NTP
messages as the primary IP address of the specified interface when sending the NTP messages. NTP
packets might not be received because of state changes of an interface on the device. To avoid that
problem, specify the loopback interface as the source interface.
When the device responds to an NTP request received, the source IP address of the NTP response is
always the destination IP address of the NTP request.