H3C Technologies H3C S3100 Series Switches - Manual (Page 471)

Operation Manual – NTP
H3C S3100-52P Ethernet Switch Chapter 1 NTP Configuration
1-9
IV. NTP multicast server mode
When an S3100-52P Ethernet switch operates in NTP multicast server mode, it
multicasts clock synchronization packets periodically. The devices in the NTP multicast
client mode will respond to these packets and start the clock synchronization process.
The switch operating in this mode can support up to 1,024 multicast clients.
Note:
z
The total number of the servers and peers configured for a switch is up to 128.
z
After the configuration, an S3100-52P Ethernet switch does not establish
connections with peers if it operates in NTP server mode. Whereas if it operates in
any of the other modes, it establishes connections with peers.
z
If an S3100-52P Ethernet switch operates in passive peer mode, NTP broadcast
client mode, or NTP multicast client mode, it establishes connections with peers
dynamically. If it operates in any of the other modes, it establishes connections with
peers statically.
1.3 Configuring Access Control Right
The access control right to the NTP server only provides a minimal degree of security
measure. A more secure way is to perform identity authentication.
The right of an access request received by the NTP server is matched from the highest
to the lowest in order of peer, server, synchronization, and query.
Table 1-3
Configure the access control right to the local NTP server
Operation Command Description
Enter system view
system-view
—
Configure the access
control right to the local
NTP server
ntp-service access
{ peer | server |
synchronization
|
query
} acl-number
Optional
By default, the access
control right to the local
NTP server is peer.
1.4 Configuring NTP Authentication
In networks with higher security requirements, the NTP authentication function must be
enabled to run NTP. Through password authentication on the client and the server, the
client is synchronized only to the server that passes the authentication. This improves
network security.