31.0 Time Synchronization with NTP
The NTP (network time protocol) mechanism is
a protocol for synchronizing the system time over the network.
First, a machine can obtain the time from a server
that is a reliable time source.
Second, a machine can itself act as a time source
for other computers in the network.
The goal is twofold—maintaining the absolute
time and synchronizing the system time of
all machines within a network.
Maintaining an exact system time is important in many situations.
The built-in hardware (BIOS) clock
does often not meet the requirements of applications like databases.
Manual correction of the system time would lead
to severe problems because, for example, a backward leap
can cause malfunction of critical applications.
Within a network, it is usually necessary
to synchronize the system time of all machines, but
manual time adjustment is a bad approach.
xntp provides an mechanism to solve these problems.
It continuously adjusts the system time
with the help of reliable time servers in the network.
It further enables the management of local reference
clocks, such as radio-controlled clocks.
