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? Any help will be appreciated.
