[prev in list] [next in list] [prev in thread] [next in thread] 

List:       opensuse
Subject:    Re: why did eth0 suddenly stop working? Again and very strange!
From:       Daniel Bauer <linux () daniel-bauer ! com>
Date:       2023-07-09 11:00:39
Message-ID: 272c3530-6bbe-caa0-a9ca-2af16915cbdd () daniel-bauer ! com
[Download RAW message or body]

Just the same as described in my first post happened again tonight:

Suddenly (like after approx. 100 of running normal) the connections on 
eth0 tpo the IP's behind the switch get lost. I can ping the switch, but 
not the other IP's connected to that switch.

There is nothing in /var/log/messages (except the camera software that 
complains for not being able to connect with the cameras). 
Networkmanager shows "connected".

Disconnect-reconnect/unplugg-replug cables/rebooting/completely 
disconnect/reconnect PC, switch and cameras from electricity doesn't help.

BUT: plugging the the switch to my laptop all IP's are available on the 
laptop immediately, then plugging back the cable to the PC they appear 
there as well...

I cannot explain to myself why when I connect the switch to my laptop 
and then back to the PC it works again immediately, but I can't 
re-establish eth0 connection by any other means. What does my laptop do 
to do the magic?

My laptop isn't connected to the PC in any way (no WiFi, no 
eth-connection), so it can't change something on the PC. To me it seems 
that it changes something on the switch, but what and how?

Any ideas how I can find the error?

Am 02.07.23 um 14:06 schrieb Daniel Bauer:
> I have some cameras connected with eth-cables to a switch and from there 
> to a computer (OS 15.5, using zoneminder for the cameras). It works.
> 
> But this morning I saw that tonight the connection to the cameras was 
> lost. I could ping the switch, but not the cameras. "arp -a" showed the 
> IP's of the cameras but with "[IP] at incomplete ...".
> 
> I checked all cables.
> I rebooted.
> I switched off/on electricity for computer/switch/cameras.
> I unplugged the switch's cable to the computer and plugged it again.
> 
> No change.
> 
> I plugged the eth cable to my laptop (that I used before for this task, 
> using OS 15.3) and all connections worked...
> 
> Plugged back the eth cable to the computer - and the connections work 
> again, all cameras pingable and visible. Magic.
> 
> There are no messages in var/log, only the zoneminder-log said "no 
> connection to..."
> 
> What happened here?
> 
> 

-- 
Daniel Bauer photographer Basel Málaga
https://www.patreon.com/danielbauer
https://www.daniel-bauer.com
[prev in list] [next in list] [prev in thread] [next in thread]