Operation Manual – NTP
Quidway S5600 Series Ethernet Switches-Release 1510
Chapter 1 NTP Configuration
Huawei Technologies Proprietary
1-8
Note:
To reduce the risk of being attacked by malicious users against opened socket and
enhance switch security, the S5600 series Ethernet switches provide the following
functions, so that a socket is opened only when it is needed:
z
Opening UDP port 123 (used for NTP) when NTP is enabled;
z
Close UDP port 123 when NTP is disabled.
The preceding functions are implemented as follows:
z
When you enable NTP by using the
ntp-service
unicast-server
,
ntp-service
unicast-peer
,
ntp-service
broadcast-client
,
ntp-service
broadcast-server
,
ntp-service
multicast-client
, or
ntp-service
multicast-server
command, UDP
port 123 is opened at the same time.
z
When you disable NTP from operating in any modes by using the
undo
forms of
the preceding six commands, UDP port 123 is closed at the same time.
I. NTP client mode
When an S5600 series switch operates in the NTP client mode,
z
The remote server identified by the
remote-ip
argument operates as the NTP
time server. The S5600 series switch operates as the client, whose clock is
synchronized to the NTP server. (In this case, the clock of the NTP server is not
synchronized to the local client.)
z
When the
remote-ip
argument is an IP address of a host, it cannot be a
broadcast or a multicast address, neither can it be the IP address of a reference
clock.
II. NTP peer mode
When an S5600 series switch operates in NTP peer mode,
z
The remote server identified by the
remote-ip
argument operates as the peer of
the S5600 series switch, and the S5600 series switch operates as the active
peer. The clock of the S5600 series switch can be synchronized to the remote
server or be used to synchronize the clock of the remote server.
z
When the
remote-ip
argument is an IP address of a host, it cannot be a
broadcast or a multicast address, neither can it be the IP address of a reference
clock.
III. NTP broadcast server mode
When an S5600 series switch operates in NTP broadcast server mode, it broadcasts
a clock synchronization packet periodically. The devices which are configured to be in
the NTP broadcast client mode will response this packet and start the clock
synchronization procedure.
