1-5
Multicast mode
Figure 1-5 Multicast mode
Client
Multicast clock synchronization
packets periodically
Network
Server
Initiates a client/server mode
request after receiving the
first multicast packet
Works in the server mode
automatically and sends
responses
Client/server mode
request
Response
Obtains the delay between the
client and server and works in
the multicast client mode
Receives multicast packets and
synchronizes the local clock
Multicast clock synchronization
packets periodically
Table 1-1 describes how the above mentioned NTP modes are implemented on the device.
Table 1-1 NTP implementation modes on the device
NTP implementation
mode
Configuration on the device
Server/client mode
Configure the local device to work in the NTP client mode. In this mode,
the remote server serves as the local time server, while the local device
serves as the client.
Symmetric peer mode
Configure the local device to work in NTP symmetric peer mode. In this
mode, the remote server serves as the symmetric-passive peer of the
device, and the local device serves as the symmetric-active peer.
Broadcast mode
z Configure the local device to work in NTP broadcast server mode. In
this mode, the local device broadcasts NTP messages through the
VLAN interface configured on the device.
z Configure the device to work in NTP broadcast client mode. In this
mode, the local device receives broadcast NTP messages through the
VLAN interface configured on the device.
Multicast mode
z Configure the local device to work in NTP multicast server mode. In
this mode, the local device sends multicast NTP messages through
the VLAN interface configured on the device.
z Configure the local device to work in NTP multicast client mode. In this
mode, the local device receives multicast NTP messages through the
VLAN interface configured on the device.
z When the device works in server mode or symmetric passive mode, you need not to perform
related configurations on this device but do that on the client or the symmetric-active peer.
z The NTP server mode, NTP broadcast mode, or NTP multicast mode takes effect only after the
local clock of the device has been synchronized.
z When symmetric peer mode is configured on two devices, to synchronize the clock of the two
devices, make sure at least one device’s clock has been synchronized.
