Configuring SNTP
Chapter 24. Configuring SNTP
24.1 Brief introduction of SNTP
The Simple Network Time Protocol Version 4 (SNTPv4), which is a subset of the Network
Time Protocol (NTP) used to synchronize computer clocks in the Internet. In common, there is
at least one server in the network, it provides reference time for clients, finally, all clients in the
network synchronized local clocks.
24.1.1 SNTP Operation Mechanism
SNTPv4 can be worked in four modes: unicast, multicast, broadcast and anycast. In
unicast mode, client actively sends a request to server, and server sends reply packet to client
according to the local time structure after receiving requirement.
In broadcast and multicast modes, server sends broadcast and multicast packets to client
periodically, and client receives packet from server passively.
In anycast mode, client actively sends request to local broadcast or multicast address, and
all servers in the network will reply to the client. Client will choose the server whose reply
packet is first received to be the server, and drops packets from others. After choosing the
server, working mode is the same as that of the unicast.
In all modes, after receiving the reply packet, client resolves this packet to obtain current
standard time, and calculates network transmit delay and local time complementary, and then
adjusts current time according them.
24.2 Configuring SNTP client
24.2.1 List of SNTP Client Configuration
Table 24-1 List of SNTP client configuration
SNTP advanced
configuration
Configure SNTP sever IP
address
Modify broadcast transfer delay