H3C Technologies H3C S3100 Series Switches - Manual (Page 696)

1-6
z Configuring NTP Server/Client Mode
z Configuring the NTP Symmetric Peer Mode
z Configuring NTP Broadcast Mode
z Configuring NTP Multicast Mode
To protect unused sockets against attacks by malicious users and improve security, H3C S3100 series
Ethernet switches provide the following functions:
z UDP port 123 is opened only when the NTP feature is enabled.
z UDP port 123 is closed as the NTP feature is disabled.
These functions are implemented as follows:
z Execution of one of the ntp-service unicast-server, ntp-service unicast-peer, ntp-service
broadcast-client, ntp-service broadcast-server, ntp-service multicast-client, and ntp-service
multicast-server commands enables the NTP feature and opens UDP port 123 at the same time.
z Execution of the undo form of one of the above six commands disables all implementation modes
of the NTP feature and closes UDP port 123 at the same time.
Configuring NTP Server/Client Mode
For switches working in the server/client mode, you only need to perform configurations on the clients,
and not on the servers.
Table 1-3 Configure an NTP client
Operation Command Description
Enter system view system-view —
Configure an NTP client
ntp-service unicast-server { remote-ip |
server-name } [ authentication-keyid key-id | priority |
source-interface Vlan-interface vlan-id | version
number ]* Required
By default, the switch is
not configured to work in
the NTP client mode.