How to monitor internet connection on drops?

Question

Computer networks

Hello. I have internet via cable, gigabit. Connected 3 months ago. Began to notice "mini-drops" in the evenings. But I do not know how to inform the provider about this - there are no logs. Therefore, I wanted to ask here - is there any software that checks the Internet connection for drops and connection loss? I want to screen this whole thing and send it to the provider, maybe something is happening there.

Answer 1

To conduct an experiment that will show at least some real data, you will need a server on the provider's network, a traffic generator (iperf3 in principle is suitable) and tcpdump or wireshark.
iperf3 itself shows how many retransmits there were, but you can additionally dump the traffic and see.
There is also an option to take a large file and download it to see if there are retransmits in wireshark. Thus, you can get more or less suitable material for further work.
And other methods like pinging and looking at "losses" or making traces using mtr will not give any useful information.
For example:

$ mtr -r -n 10 ya.ru
Start: 2021-12-06T00:20:05+0300
HOST: zbook                       Loss%   Snt   Last   Avg  Best  Wrst StDev
Start: 2021-12-06T00:20:20+0300
HOST: zbook                       Loss%   Snt   Last   Avg  Best  Wrst StDev
  1.|-- 192.168.254.254            100.0%    10    2.0   4.1   1.3  25.3   7.5
  2.|-- 212.1.254.166              0.0%    10    1.9   1.8   1.3   2.0   0.3
  3.|-- 212.1.238.184              0.0%    10    1.3   1.9   1.3   2.5   0.5
  4.|-- 212.1.239.202              0.0%    10    6.4   6.6   6.0   8.1   0.6
  5.|-- 89.20.133.47               0.0%    10    7.0   9.6   7.0  31.1   7.5
  6.|-- ???                       100.0    10    0.0   0.0   0.0   0.0   0.0
  7.|-- 87.250.250.242             0.0%    10   17.3  18.1  17.3  20.1   0.7

On the first hop 100% "smack", it turns out that the Internet does not work at all? But how then the traffic passes through 7 more routers? And on the 6th hop, what kind of "loss"?
The answer is simple: in order to protect itself from overloading its weak CPU, the router discards unnecessary ICMP or blocks them altogether, hence the "losses", and user traffic is processed not by the weak CPU of the router, but by specialized ASIC chips, and in order to "push" it, you still need to try.
And remember, the provider is only responsible for the section of the network controlled by him, the provider cannot be responsible for the poor quality of an arbitrary server on the Internet.
For reference Traceroute: about the ability to read the output

Answer 2

mtr (console, linux) or simpler winmtr
pings not only the target but also intermediate servers on the network, allowing you to identify exactly where the problem is