IP and DNS
The preceding information was supplied by the NTP server to the client. This
information can be used to determine the accuracy of the supplied time server. For
example, the stratum value 2 indicates that the NTP server will query another NTP
server with the stratum value 1, which may have a directly attached time source. For
more information about the NTP protocol, you may either read the RFC 958 document
at https://tools.ietf.org/html/rfc958 or visit http://www.ntp.org/.
Inspecting the NTP client/server communication
You may be able to learn more about NTP by looking at captured packets. For this
purpose, the preceding NTP client/server communication has been captured as
shown in the following two screenshots:
The first screenshot shows the NTP client request. If you look inside the flag fields,
then you will see the client's version number.