3Com S7906E - Switch, Configuration Manual

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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 in the Security Volume .
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.
Configuring NTP Authentication
The NTP authentication feature should be enabled for a system running NTP in a network where there
is a high security demand. This feature enhances the network security by means of client-server key
authentication, which prohibits a client from synchronizing with a device that has failed authentication.
Configuration Prerequisites
The configuration of NTP authentication involves configuration tasks to be implemented on the client
and on the server.
When configuring the NTP authentication feature, pay attention to the following principles:
z
For all synchronization modes, when you enable the NTP authentication feature, you should
configure an authentication key and specify it as a trusted key. Namely, the ntp-service
authentication enable command must work together with the ntp-service authentication-keyid
command and the ntp-service reliable authentication-keyid command. Otherwise, the NTP
authentication function cannot be normally enabled.
z
For the client/server mode or symmetric mode, you need to associate the specified authentication
key on the client (symmetric-active peer if in the symmetric peer mode) with the corresponding
NTP server (symmetric-passive peer if in the symmetric peer mode). Otherwise, the NTP
authentication feature cannot be normally enabled.
z
For the broadcast server mode or multicast server mode, you need to associate the specified
authentication key on the broadcast server or multicast server with the corresponding NTP server.
Otherwise, the NTP authentication feature cannot be normally enabled.