I have here a laptop with Linux Mint 20.3. Seems that exactly every 5 minutes my wired network connection is reconnecting. For determining that I have getting the UUID of my wired interface:
mcli connection
NAME UUID TYPE DEVICE
Kabelgebundene Verbindung 1 7805205a-4e9a-35d6-9c07-dcea2c7a2975 ethernet enp1s0f1
...
And I have written following script (where I search the last connecting time for the interface with the above UUID in /var/lib/NetworkManager/timestamps):
#!/bin/sh
echo "---" | tee -a /root/tmp/term.log
echo -n "current time : " | tee -a /root/tmp/term.log
date | tee -a /root/tmp/term.log
echo -n "Last wired connect : " | tee -a /root/tmp/term.log
date --date=@"$( grep "7805205a-4e9a-35d6-9c07-dcea2c7a297" /var/lib/NetworkManager/timestamps | awk -F'=' 'BEGIN {var=0}{if(var<$2) var=$2;} END{print var}' )" | tee -a /root/tmp/term.log
echo "" | tee -a /root/tmp/term.log
This script I call via watch:
watch -n 1 tmp/connLog.sh
And I get:
---
current time : Di 21. Jun 16:55:55 CEST 2022
Last wired connect : Di 21. Jun 16:55:54 CEST 2022
...
...
---
current time : Di 21. Jun 17:00:55 CEST 2022
Last wired connect : Di 21. Jun 17:00:54 CEST 2022
...
...
---
current time : Di 21. Jun 17:05:55 CEST 2022
Last wired connect : Di 21. Jun 17:05:54 CEST 2022
...
In /var/log/syslog I don't get any interesting infos, e.g. for the time 17:05:54:
Jun 21 17:05:31 laptop-ste ntpd[751584]: 141.95.116.43 local addr 192.168.1.36 -> <null>
Jun 21 17:05:32 laptop-ste mount.davfs: Die Größe der offenen Dateien überschreitet die maximale Größe des Cache um 0 MiBytes
Jun 21 17:06:50 laptop-ste kernel: [36701.012660] [UFW BLOCK] IN=enp1s0f1 OUT= MAC=01:00:5e:00:00:01:98:9b:cb:bf:c3:7e:08:00 SRC=192.168.1.254 DST=224.0.0.1 LEN=36 TOS=0x00 PREC=0xC0 TTL=1 ID=32721 DF PROTO=2
Anybody has an idea why the network connection will be reconnect each 5 minutes?
