1
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Now something to point out in the ICMP message NPM is inserting data so the NPM server 10 1 100 100

2
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is sending an echo request but is including data in the message NPM does this by default.

3
00:00:17,530 --> 00:00:23,710
And one of the reasons for doing this is that some devices between your enemies and the device that

4
00:00:23,710 --> 00:00:30,640
you pinging may block ICMP packets with certain criteria in the data fields.

5
00:00:30,700 --> 00:00:37,480
Some firewalls as an example may block packets with a zero sized data field and some firewalls will

6
00:00:37,480 --> 00:00:40,250
block packets with large payloads.

7
00:00:40,360 --> 00:00:47,560
Some devices even block ICMP packets that are even audience size in this capture we can see that the

8
00:00:47,590 --> 00:00:53,510
response packet was sent from right to to the animus.

9
00:00:53,590 --> 00:01:00,790
So it's an ICMP echo reply message and the animus will calculate the difference between the time that

10
00:01:00,790 --> 00:01:08,800
the request was sent and the reply received and it uses that to calculate the round trip response time

11
00:01:09,370 --> 00:01:10,870
or latency of the network.