H3C Technologies H3C S3100 Series Switches - Manual (Page 697)

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z The remote server specified by remote-ip or server-name serves as the NTP server, and the local
switch serves as the NTP client. The clock of the NTP client will be synchronized by but will not
synchronize that of the NTP server.
z remote-ip cannot be a broadcast address, a multicast address or the IP address of the local clock.
z After you specify an interface for sending NTP messages through the source-interface keyword,
the source IP address of the NTP message will be configured as the primary IP address of the
specified interface.
z A switch can act as a server to synchronize the clock of other switches only after its clock has been
synchronized. If the clock of a server has a stratum level lower than or equal to that of a client’s
clock, the client will not synchronize its clock to the server’s.
z You can configure multiple servers by repeating the ntp-service unicast-server command. The
client will choose the optimal reference source.
Configuring the NTP Symmetric Peer Mode
For switches working in the symmetric peer mode, you need to specify a symmetric-passive peer on the
symmetric-active peer.
Table 1-4 Configure a symmetric-active switch
Operation Command Description
Enter system view system-view —
Specify a
symmetric-passive peer
for the switch
ntp-service unicast-peer { remote-ip |
peer-name } [ authentication-keyid key-id |
priority | source-interface Vlan-interface
vlan-id | version number ]*
Required
By default, a switch is not
configured to work in the
symmetric mode.