3Com 4500 Switch User Manual


 
1-10
To do… Use the command… Remarks
Enter system view
system-view
Enter VLAN interface view
interface Vlan-interface
vlan-id
Configure the switch to work in
the NTP multicast client mode
ntp-service multicast-client
[ ip-address ]
Required
Not configured by default.
Configuring Access Control Right
With the following command, you can configure the NTP service access-control right to the local switch
for a peer device. There are four access-control rights, as follows:
z query: Control query right. This level of right permits the peer device to perform control query to the
NTP service on the local device but does not permit the peer device to synchronize its clock to the
local device. The so-called “control query” refers to query of state of the NTP service, including
alarm information, authentication status, clock source information, and so on.
z synchronization: Synchronization right. This level of right permits the peer device to synchronize
its clock to the local switch but does not permit the peer device to perform control query.
z server: Server right. This level of right permits the peer device to perform synchronization and
control query to the local switch but does not permit the local switch to synchronize its clock to the
peer device.
z peer: Peer access. This level of right permits the peer device to perform synchronization and
control query to the local switch and also permits the local switch to synchronize its clock to the
peer device.
NTP service access-control rights from the highest to the lowest are peer, server, synchronization,
and query. When a device receives an NTP request, it will perform an access-control right match in this
order and use the first matched right.
Configuration Prerequisites
Prior to configuring the NTP service access-control right to the local switch for peer devices, you need
to create and configure an ACL associated with the access-control right. For the configuration of ACL,
refer to ACL Configuration in Security Volume.
Configuration Procedure
Follow these steps to configure the NTP service access-control right to the local device for peer
devices:
To do… Use the command… Remarks
Enter system view
system-view
Configure the NTP service
access-control right to the local
switch for peer devices
ntp-service access { peer |
server | synchronization |
query } acl-number
Optional
peer by default