3Com WX3000 operation manual Multicast mode, NTP implementation Configuration on the device Mode

Multicast mode

Figure 1-5Multicast mode

Server Client

Works in the server mode automatically and sends responses

Network

Multicast clock synchronization packets periodically

Client/server mode

request

Response

Multicast clock synchronization

packets periodically

Initiates a client/server mode request after receiving the first multicast packet

Obtains the delay between the client and server and works in the multicast client mode

Receives multicast packets and synchronizes the local clock

Table 1-1 describes how the above mentioned NTP modes are implemented on the device.

Table 1-1NTP implementation modes on the device

NTP implementation		Configuration on the device
mode
	Configure the local device to work in the NTP client mode. In this mode,
Server/client mode	the remote server serves as the local time server, while the local device
	serves as the client.
	Configure the local device to work in NTP symmetric peer mode. In this
Symmetric peer mode	mode, the remote server serves as the symmetric-passive peer of the
	device, and the local device serves as the symmetric-active peer.
		z Configure the local device to work in NTP broadcast server mode. In
		this mode, the local device broadcasts NTP messages through the
Broadcast mode		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.
		z Configure the local device to work in NTP multicast server mode. In
		this mode, the local device sends multicast NTP messages through
Multicast mode		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

z

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.

The NTP server mode, NTP broadcast mode, or NTP multicast mode takes effect only after the local clock of the device has been synchronized.

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.

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