R3166-R3206-HP High-End Firewalls System Management and Maintenance Configuration Guide-6PW101

92
NOTE:
• Whether the ntp-service refclock-master command is supported depends on your device models.
• Typically, the stratum level of the NTP server which 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 themselves to it. The synchronization distances between the primary
reference source and other devices on the network, namely, the number of NTP servers on the NTP
synchronization paths, determine the clock stratum levels of the devices.
• After you have configured the local clock as a reference clock, the local device can act as a reference
clock to synchronize other devices in the network. Therefore, perform this confi
g
uration with caution to
avoid clock errors of the devices in the network.
• In this command,
ip-address mu st b e 127.127.1.u , where u ran
g
es 0 to 3, representin
g
the NTP process
ID.
Configuring optional parameters of NTP
Specifying 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.
When the device responds to an NTP request received, the source IP address of the NTP response
is always the IP address of the interface that received the NTP request.
Following these steps to specify the source interface for NTP messages:
To do… Use the command…
Remarks
Enter system view system-view —
Specify the source
interface for NTP
messages
ntp-service source-interface
interface-type
interface-number
Required
By default, no source interface is specified for NTP
messages, and the system uses the IP address of the
interface determined by the matching route as the
source IP address of NTP messages.
CAUTION:
• If you have specified the source interface for NTP messages in the ntp-service unicast-server or
ntp-service unicast-peer command, the interface specified in the ntp-service unicast-server or
ntp-service unicast-peer command serves as the source interface of NTP messages.
• If you have configured the ntp-service broadcast-server or ntp-service multicast-server command, the
source interface of the broadcast or multicast NTP messages is the interface configured with the
respective command.
• If the specified source interface for NTP messa
g
es is down, the source IP address for an NTP messa
g
e
that is sent out is the primary IP address of the outgoing interface of the NTP message.
Disabling an interface from receiving NTP messages
When NTP is enabled, NTP messages can be received from all the interfaces by default, and you can
disable an interface from receiving NTP messages through the following configuration.