H3C S5500-SI Series, Operation Manual

Page: 1161 / 1217

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In the ntp-service unicast-server command, ip-address must be a unicast address, rather than a
broadcast address, a multicast address or the IP address of the local clock.
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When the source interface for NTP messages is specified by the source-interface argument, the
source IP address of the NTP messages will be configured as the primary IP address of the
specified interface.
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A device can act as a server to synchronize the clock of other devices only after its clock has been
synchronized. If the clock of a server has a stratum level higher than or equal to that of a client’s
clock, the client will not synchronize its clock to the server’s.
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You can configure multiple servers by repeating the ntp-service unicast-server command. The
clients will choose the optimal reference source.
Configuring the NTP Symmetric Peers Mode
For devices working in the symmetric mode, you need to specify a symmetric-passive peer on a
symmetric-active peer.
Following these steps to configure a symmetric-active device:
To do… Use the command… Remarks
Enter system view system-view —
Specify a symmetric-passive
peer for the device
ntp-service unicast-peer
{ ip-address | peer-name }
[ authentication-keyid keyid |
priority | source-interface
interface-type interface-number
| version number ] *
Required
No symmetric-passive peer is
specified by default.
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In the symmetric mode, you should use any NTP configuration command in Configuring the
Operation Modes of NTP to enable NTP; otherwise, a symmetric-passive peer will not process
NTP messages from a symmetric-active peer.
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In the ntp-service unicast-peer command, ip-address must be a unicast address, rather than a
broadcast address, a multicast address or the IP address of the local clock.
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When the source interface for NTP messages is specified by the source-interface argument, the
source IP address of the NTP messages will be configured as the primary IP address of the
specified interface.
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Typically, at least one of the symmetric-active and symmetric-passive peers has been
synchronized; otherwise the clock synchronization will not proceed.
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You can configure multiple symmetric-passive peers by repeating the ntp-service unicast-peer
command.