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To understand the working of the network
time protocol, you need to understand about stratum.

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It's all
about reliability.

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The highest level of
reliability is the atomic clock.

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That's because atomic clocks are highly accurate in terms
of stratum. The atomic clock is getting Stratum 1.

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Now, in time synchronization, you might have
servers that synchronize directly with the atomic clock.

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And if you have a server that
synchronizes with the atomic clock, well, it gets

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the stratum of two, which indicates that
they are very close to the time source.

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Now, if you have another
level of time servers that is

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synchronizing with the Stratum 2
server, then these get Stratum 3.

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And then there is you, your local server
that needs to make a choice how to synchronize.

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Now, how is that going to work? Well,
typically the server is reaching out to multiple servers.

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Let's say 1 stratum 2,
1 stratum 3, 1 stratum 1.

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And then the NTP
server has a choice.

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So that means that you have three different servers. And if
everything is going all right, you get the time from three

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different, different servers. And if one of these servers drops,
then there is no problem. Now, it's very easy to understand.

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Your local NTP process will always go for
the highest stratum. So if it can reach

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the atomic clock, you will get a Stratum
2 on your own server. Which means that

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if you are synchronizing as a Stratum 2
with this Stratum 3 server, well, that's interesting.

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You will never synchronize with that because
yourself you are more reliable. Right now you

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can also configure your own server with
its local stratum for local time configuration. It's

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pretty common as a backup that
your server is synchronized as stratum 10.

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And that means that you indicate that
your stratum is not very reliable. But

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if anything goes wrong in the Internet
communication and other time clients in your

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network needs time, they can always
fetch the time from your local server.

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Sometimes you will also find that
a stratum of 16 is communicate well.

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If 16 is communicated, that means
that this time server is not reliable.

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So that will be excluded
from synchronization in the NTP protocol.