H3C Technologies H3C S5120 Series Switches - Manual (Page 570)

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Configuring NTP Multicast Mode
Network requirements
As shown in Figure 1-10 , Switch C functions as the NTP server for multiple devices on different network
segments and synchronizes the time among multiple devices. To realize this requirement, perform the
following configurations:
z Switch C’s local clock is to be used as a reference source, with the stratum level of 2.
z Switch C works in the multicast server mode and sends out multicast messages from
VLAN-interface 2.
z Switch A and Switch D work in the multicast client mode and receive multicast messages through
VLAN-interface 3 and VLAN-interface 2 respectively.
In this example, Switch B is a L3 switch and it must support the multicast function.
Figure 1-10 Network diagram for NTP multicast mode configuration
Configuration procedure
1) Configure IP addresses for interfaces (omitted)
2) Configuration on Switch C:
# Configure Switch C to work in the multicast server mode and send multicast messages through
VLAN-interface 2.
[SwitchC] interface vlan-interface 2
[SwitchC-Vlan-interface2] ntp-service multicast-server
3) Configuration on Switch D:
# Configure Switch D to work in the multicast client mode and receive multicast messages on
VLAN-interface 2.
system-view
[SwitchD] interface vlan-interface 2
[SwitchD-Vlan-interface2] ntp-service multicast-client