3Com 4210G Series Configuration Manual page 1061

NTP server (symmetric-passive peer if in the symmetric peer mode). Otherwise, the NTP
authentication feature cannot be normally enabled.
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.
For the client/server mode, if the NTP authentication feature has not been enabled for the client,
the client can synchronize with the server regardless of whether the NTP authentication feature
has been enabled for the server or not. If the NTP authentication is enabled on a client, the client
can be synchronized only to a server that can provide a trusted authentication key.
For all synchronization modes, the server side and the client side must be consistently configured.
Configuration Procedure
Configuring NTP authentication for a client
Follow these steps to configure NTP authentication for a client:
To do...
Enter system view
Enable NTP
authentication
Configure an NTP
authentication key
Configure the key as a
trusted key
Associate the specified
key with an NTP server
After you enable the NTP authentication feature for the client, make sure that you configure for the
client an authentication key that is the same as on the server and specify that the authentication key is
trusted; otherwise, the client cannot be synchronized to the server.
Use the command...
system-view
ntp-service authentication enable
ntp-service authentication-keyid
keyid authentication-mode md5
value
ntp-service reliable
authentication-keyid keyid
Client/server mode:
ntp-service unicast-server
{ ip-address | server-name }
authentication-keyid keyid
Symmetric peers mode:
ntp-service unicast-peer
{ ip-address | peer-name }
authentication-keyid keyid
25-13
Remarks
—
Required
Disabled by default
Required
No NTP authentication key by
default
Required
No authentication key is
configured to be trusted by
default.
Required
You can associate a
non-existing key with an NTP
server. To enable NTP
authentication, you must
configure the key and specify it
as a trusted key after
associating the key with the
NTP server.