From: Daniel Bauer <linux@daniel-bauer.com> Date: Sun, 9 Jul 2023 13:00:39 +0200 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? The only think I can think of that would cause this behavior is that somehow the switch is being fooled into thinking that the Ethernet address for that port has changed when in fact it hasn't. (That should only explain failure to receive packets, but depending on the nature of the failure, it might screw up sending as well.) Plugging in another system forces the switch to reconsider, which fixes the problem. And if attempting to make connections from your PC fails, then it's not surprising that unplugging/replugging doesn't help either. This also goes a long way to proving that it's not your PC's fault. Have you tried permuting the connections to the switch? (And sorry if this has already been suggested.) ================ From: Daniel Bauer <linux@daniel-bauer.com> Date: Sun, 9 Jul 2023 14:32:04 +0200 Am 09.07.23 um 13:18 schrieb Carlos E. R.:
Ah, then you did you power cycle the switch?
Yes How long did you leave it unplugged? Small switches don't need much power, so if they have an even halfway decent power supply, they can remember routing information for a surprisingly long time, perhaps a few minutes even. Or there may even be an NVRAM cache for routing info. -- Bob Rogers http://www.rgrjr.com/