Στις 2020-03-03 23:34, Miguel A. Vallejo έγραψε:
Hello! Diagnosing one of my several problems with WiFi in Debian I found a problem this time not related to the WiFi connection itself, but I don't know how to get the culprit... Anyone can point me in the right direction? Symptoms: From time to time I lost Internet connection for a period of about 5 to 30 minutes. It happens at least two or three times a day. Setup: Desktop computer (192.168.1.2) running Debian Buster amd64 with current kernel 4.19.98-1 connected via WiFi to router / gateway (192.168.1.1). Wifi Adapter is MT7612U from Mediatek. While connection is lost: - I can launch wavemon and I can confirm the WiFi adapter is still connected and sending / receiving packets and beacons. - Arp command shows the gateway HWaddress as incomplete. - Launching Wireshark in the desktop computer I can see incoming packets from other devices, but I can also see a "Who has 192.168.1.1? Tell 192.168.1.2" ARP requests from my desktop every second. At first glance it seems the gateway isn't responding to my arp requests, but... - I can see arp queries from the gateway to my desktop, and I can see the responses, but they seem they never reach the gateway. - Forcing network activity with my smartphone, I can see also arp requests from the smartphone answered by the desktop, but a ping from the smartphone to the desktop machine gives no response. Of course the phone can use internet without any problem using the same gateway. - If I unplug and replug the WiFi adapter everything works again. If I left the WiFi adapter plugged, eventually I get an arp response from the gateway, and everything works normally again. This may take up to 20-30 minutes. Only once the wifi connection crashed after several minutes. It seems that when I lost connectivity I can't sent arp messages but I can receive them. They are sent, I can see them with Wireshark, but it seems they will never get outside the machine. I searched for known bugs but I wasn't able to find anything, only a message from an Ubuntu user aparently having the same problem, but with a different WiFi adapter and kernel version (4.18 I think): https://askubuntu.com/questions/1122683/no-internet-access-after-random-intervals-in-ubuntu-18-04-2-lts The problem is now I don't know how to get the culprit of this bug. Is the kernel? Is the Mediatek kernel module?
I would check the `dmesg` command output. If there are erros there then they re coming from the kernel. Have you made sure that the wifi is not the problem? Before going into wild software investigation? For example have you tried in a Windows laptop with the correct device drivers? Because you even might not be using the correct device drivers!
Any help will be appreciated.
--- Regards, Nektarios Katakis