H3C S7500E Series Ethernet Switches Operation Manual

Operation Manual – NTP
H3C S7500E Series Ethernet Switches Chapter 1 NTP Configuration
1-11
 Note:
z In the symmetric mode, you should use the ntp-service refclock-master command
or any NTP configuration command in
Configuring the Operation Modes of NTP to
enable NTP; otherwise, a symmetric-passive peer will not process NTP packets
from a symmetric-active peer.
z In the ntp-service unicast-peer command, ip-address must be a host address,
rather than a broadcast address, a multicast address or the IP address of the local
clock.
z When the interface used to send NTP messages is specified by the
source-interface argument, the source IP address of the NTP message will be
configured as the primary IP address of the specified interface.
z Typically, at least one of the symmetric-active and symmetric-passive peers has
been synchronized; otherwise the clock synchronization will not proceed.
z You can configure multiple symmetric-passive peers by repeating the ntp-service
unicast-peer command.
1.2.3 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 mode sends a reply and synchronizes its local clock.
For devices working in the broadcast mode, you need to configure both the server and
clients. Because an interface need 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, the NTP broadcast mode can be
configured only in the specific interface view.
I. Configuring a broadcast client
To do… Use the command… Remarks
Enter system view
system-view
—
Enter interface view
interface interface-type
interface-number
Required
Enter the interface used to
receive NTP broadcast
messages
Configure the device to
work in the NTP
broadcast client mode
ntp-service
broadcast-client
Required