Large losses in the network, what to do?

Question

linux

The situation is as follows, in the local network there are packet losses from 10-20 percent, several networks with public addresses are used inside, one from the provider and one rented, the losses are not chaotic, and monitoring showed (worldping) that every two and a half minutes.
I pinged the router that serves these networks, everything is fine with it, tell someone how deeply you can analyze the behavior of the packets. why and where they are lost,
what tools to use, otherwise I still do not understand at all what is happening with this anomaly.
PS we rented part of the addresses and the European registrar, and now our local provider distributes these addresses via bgp, can there be a problem with incorrect BGP settings, and that TTL packets may be lost somewhere, well, or some other magic chips can affect this.
The switches are stupid and will not connect via ssh, they almost cannot give information, well, how can you set up mirroring.

Answer 1

The problem was solved, it was some kind of anomaly, the provider did not admit his guilt for a long time, in the end he changed the equipment, they said that they themselves still cannot understand what the joke was

Answer 2

Draw a network diagram, for starters, with beautiful icons and addresses of routers, switches, hosts. Use mtr or pingplotter
to find the loss location . If the losses are in the local segment - see the download, maybe you have something generating traffic to the ceiling there. See statistics on interfaces, errors, drops. If nothing like that, start changing settings, patch cords, network cards, switches, routers.

Answer 3

Because of bgp - maybe.
Record the traffic at its highest point and analyze it using wireshark for example. In traffic, most likely everything will be visible. And this problem can be due to many reasons.

Answer 4

There is little information and it is not entirely clear. Make an example with fictitious addresses, where you ping and where packets are lost. There could be many reasons for this.