From opensuse Mon Jul 10 08:37:27 2023 From: Daniel Bauer Date: Mon, 10 Jul 2023 08:37:27 +0000 To: opensuse Subject: Re: why did eth0 suddenly stop working? Message-Id: <26e5243d-f586-d976-4b02-275a08aceb94 () daniel-bauer ! com> X-MARC-Message: https://marc.info/?l=opensuse&m=168897818215820 Am 09.07.23 um 20:39 schrieb Carlos E. R.: > On 2023-07-02 14:06, Daniel Bauer wrote: >> 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? > > Your setup is, I think: > > > +-----------------------------------+ > |    switch 8 mouths                | > |                                   | > +-----------------------------------+ >   |      |      |       |       | >   |      |      |       |       | > mini    cam    cam    cam     router > pc       1      2      3 > > > Normally, it all works. > > When it fails: > >  ping from mini pc to sw, works Not sure anymore, I think the switch itself has no IP (?). What works is ping to eth0, with the fixed IP I defined in networkmanager. >  ping from mini pc to camera, fails yes >  ping to router? There is no router. Only Mini_PC to switch, switch to cameras. WiFi is turned off. No internet connection wanted. >  ping to laptop (tried)? Haven't tried. Need another cable. Will try while everything works to check the new cable, and then try again, when the error occurs the next time. > > The SW has to be involved in the failure somehow. The culprit can not be > your computer alone. I posted on it's forum yesterday, with not a lot of hope, because actually I cannot imagine that a software could stop my network working, especially because it's the same on the laptop and on the PC. But well... -- Daniel Bauer photographer Basel Málaga https://www.patreon.com/danielbauer https://www.daniel-bauer.com