H3C Technologies H3C S5120 Series Switches - Manual (Page 562)

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Configuring Access-Control Rights
With the following command, you can configure the NTP service access-control right to the local device.
There are four access-control rights, as follows:
z query: control query permitted. This level of right permits the peer devices to perform control query
to the NTP service on the local device but does not permit a peer device to synchronize its clock to
that of the local device. The so-called “control query” refers to query of some states of the NTP
service, including alarm information, authentication status, clock source information, and so on.
z synchronization: server access only. This level of right permits a peer device to synchronize its
clock to that of the local device but does not permit the peer devices to perform control query.
z server: server access and query permitted. This level of right permits the peer devices to perform
synchronization and control query to the local device but does not permit the local device to
synchronize its clock to that of a peer device.
z peer: full access. This level of right permits the peer devices to perform synchronization and control
query to the local device and also permits the local device to synchronize its clock to that of a peer
device.
From the highest NTP service access-control right to the lowest one are peer, server,
synchronization, and query. When a device receives an NTP request, it will perform an
access-control right match and will use the first matched right.
Configuration Prerequisites
Prior to configuring the NTP service access-control right to the local device, you need to create and
configure an ACL associated with the access-control right. For the configuration of ACL, refer to ACL
Configuration.
Configuration Procedure
Follow these steps to configure the NTP service access-control right to the local device:
To do… Use the command… Remarks
Enter system view system-view —
Configure the NTP service
access-control right for a peer
device to access the local
device
ntp-service access { peer |
query | server |
synchronization } acl-number
Required
peer by default
The access-control right mechanism provides only a minimum degree of security protection for the
system running NTP. A more secure method is identity authentication.