16
NOTE:
•
In
the
ntp-service unicast-server
command, ip-address must be a unicast address. It cannot be a
broadcast address, a multicast address or the IP address of the local clock.
•
When the source interface for NTP messages is specified by the
source-interface
keywor
d, the source
IP address of the NTP message
s is configured as the primary IP address of the specified interface.
•
A device can act as a server to synchronize the clock of other devices only after its clock has been
synchronized. If the clock of a server has
a stratum level higher than or equal to that of a client’s
clock, the client will not synchronize its clock to th
at server’s clock.
•
You can configure multiple servers by repeating the
ntp-service unicast-server
command. The clients
will select the optimal
reference source.
Configuring the NTP symmetric peers mode
For devices working in symmetric mode, specify a symmetric-passive peer for a symmetric-active peer.
Following these steps to specify a symmetric-passive peer on the active peer:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Specify a
symmetric-passive peer for
the device
ntp-service
unicast-peer
{
ip-address
|
peer-name
} [
authentication-keyid
keyid
|
priority
|
source-interface
interface-type
interface-number
|
version
number
] *
Required
No symmetric-passive peer is
specified by default.
NOTE:
•
In symmetric mode, use the any NTP configuration command in
Configuring the operation modes of
to enable NTP. Otherwise, a symmetric-passive peer will not process NTP messages from a
symmetric-active peer.
•
In the
ntp-service
unicast-peer
command,
ip-address must be a unicast address, rather than a
broadcast address, a multicast address or the IP address of the local clock.
•
When the source interface for NTP messages is specified by the
source-interface
keyword, the source IP
address of the NTP messages is configured as the primary IP address of the specified interface.
•
Typically, at least one of the symmetric-active and symmetric-passive peers has been synchronized.
Otherwise the clock synchronization will not proceed.
•
You can configure multiple symmetric-passive peers by repeating the
ntp-service
unicast-peer
command.
Configuring NTP broadcast mode
The broadcast server periodically sends NTP broadcast messages to the broadcast address
255.255.255.255. After receiving the messages, the device working in NTP broadcast client mode
sends a reply and synchronizes its local clock.
For devices working in broadcast mode, configure both the server and the clients. NTP broadcast mode
can be configured only in the specific interface view, because an interface needs to be specified on the
broadcast server for sending NTP broadcast messages and an interface also needs to be specified on
each broadcast client for receiving broadcast messages.