HP 4800G Series Configuration Manual page 1908

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Configuring NTP Multicast Mode
Network requirements
The local clock of Switch C is to be used as the master clock, with a stratum level of 2.
Switch C works in the multicast server mode and sends out multicast messages from
VLAN-interface 2.
Switch A and Switch D work in the multicast client mode and receive multicast messages through
VLAN-interface 3 and VLAN-interface 2 respectively.
Figure 1-10 Network diagram for NTP multicast mode configuration
Vlan-int3
1.0.1.11/24
Switch A
Configuration procedure
1) Configuration on Switch C:
# Configure Switch C to work in the multicast server mode and send multicast messages through
VLAN-interface 2.
<SwitchC> system-view
[SwitchC] interface vlan-interface 2
[SwitchC-Vlan-interface2] ntp-service multicast-server
2) Configuration on Switch D:
# Configure Switch D to work in the multicast client mode and receive multicast messages on
VLAN-interface 2.
<SwitchD> system-view
[SwitchD] interface vlan-interface 2
[SwitchD-Vlan-interface2] ntp-service multicast-client
Because Switch D and Switch C are on the same subnet, Switch D can receive the multicast messages
from Switch C without being enabled with the multicast functions and can be synchronized to Switch C.
# View the NTP status of Switch D after clock synchronization.
[SwitchD-Vlan-interface2] display ntp-service status
Clock status: synchronized
Clock stratum: 3
Reference clock ID: 3.0.1.31
1
Vlan-int3 Vlan-int2
1.0.1.10/24 3.0.1.30/24
Switch B
Vlan-int2
3.0.1.31/24
Switch C
Vlan-int2
3.0.1.32/24
Switch D
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