3Com S7906E - Switch, Configuration Manual

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1-13
Disabling an Interface from Receiving NTP Messages
When NTP is enabled, NTP messages can be received from all the interfaces by default, and you can
disable an interface from receiving NTP messages through the following configuration.
To do… Use the command… Remarks
Enter system view system-view —
Enter interface view
interface interface-type
interface-number
—
Disable the interface from
receiving NTP messages ntp-service in-interface
disable
Required
An interface is enabled to
receive NTP messages by
default.
Configuring the Maximum Number of Dynamic Sessions Allowed
To do… Use the command… Remarks
Enter system view system-view —
Configure the maximum
number of dynamic sessions
allowed to be established
locally
ntp-service
max-dynamic-sessions
number
Required
100 by default
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.