Operation Manual – NTP
H3C S3100 Series Ethernet Switches
Chapter 1 NTP Configuration
1-7
1.3 Configuring NTP Implementation Modes
An S3100 Ethernet switch can work in one of the following NTP modes:
z
Configuring NTP Server/Client Mode
z
Configuring the NTP Symmetric Peer Mode
z
Configuring NTP Broadcast Mode
z
Configuring NTP Multicast Mode
Note:
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.
1.3.1 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.