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   SolSoCoG (solsocog@ieji.de)'s status on Tuesday, 25-Jul-2023 19:37:17 JST SolSoCoG

   How can I clear up an udp4 port that is held open but has no pid attached to it? Neither nfs nor wireguard are keeping that port up. Also nothing in /proc/*/fd/* when searching for the inode that keeps the port open. What the heck? It was used by a gameserver which I sigkilled, now this *ghost* port stays open and blocks further attemps to bind to that port. Shown in /proc/net/udp is uid 0 and a lot of drops at that port. #linux #networking #debian

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     oheso (oheso@ieji.de)'s status on Tuesday, 25-Jul-2023 19:44:47 JST oheso

     in reply to

     @SolSoCoG Reboot? Actually sir I have no idea.

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     SolSoCoG (solsocog@ieji.de)'s status on Tuesday, 25-Jul-2023 19:47:45 JST SolSoCoG

     in reply to

     • oheso

     @oheso I am also quite flabbergasted by this phenomenon. But do I want to reboot the server each time a process sh*ts itself in a very peculiar port blocking way? :crychkat3r:

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     Anselm Schüler (anselmschueler@ieji.de)'s status on Tuesday, 25-Jul-2023 19:49:35 JST Anselm Schüler

     in reply to

     @SolSoCoG Maybe https://serverfault.com/questions/181015/how-do-you-free-up-a-port-being-held-open-by-dead-process#273727 is of use?

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     SolSoCoG (solsocog@ieji.de)'s status on Tuesday, 25-Jul-2023 20:05:23 JST SolSoCoG

     in reply to

     • Anselm Schüler

     @anselmschueler thats not the answer unfortunately, thanks for the effort though. lsof -i :port shows nothing, ss -tulpn shows udp UNCONN 262656 and no corresponding pid/program, it still has stuff in Recv-Q. The conan exiles server went and ghostblocked udp ports 7777/7778 and started on 7779 7780 the next time I started it because the first two are indefinitely blocked.

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     Anselm Schüler (anselmschueler@ieji.de)'s status on Tuesday, 25-Jul-2023 20:05:58 JST Anselm Schüler

     in reply to

     @SolSoCoG So there's no child of the dead process still around?

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     SolSoCoG (solsocog@ieji.de)'s status on Tuesday, 25-Jul-2023 20:09:17 JST SolSoCoG

     in reply to

     • Anselm Schüler

     @anselmschueler I checked, its just /opt/wine-stable/bin/wineserver, C:\windows\system32\winedevice.exe and /bin/sh /usr/bin/xvfb-run --auto-servernum --server-args=-screen 0 640x480x24:32 wine64 ./ConanSandboxServer.exe thats the bare minimum number of processes to run the conan server under wine

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     oheso (oheso@ieji.de)'s status on Tuesday, 25-Jul-2023 20:16:07 JST oheso

     in reply to

     @SolSoCoG No (which you well know ;-) )

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     SolSoCoG (solsocog@ieji.de)'s status on Tuesday, 25-Jul-2023 20:23:47 JST SolSoCoG

     in reply to

     • oheso

     @oheso If i could just tell something to free a port by the /proc/net/udp sl, because that is how far I can track the port. Wait can I try to use the pointer from the udp file to find the culprit?🤔

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     Delta Lead (deltalead@ieji.de)'s status on Tuesday, 25-Jul-2023 20:42:07 JST Delta Lead

     in reply to

     @SolSoCoG is it listed in /proc/net/udp? Also, could be the owning process hasn't be reaped by its parent so it is in a zombie state and therefore holding onto socket.

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     SolSoCoG (solsocog@ieji.de)'s status on Tuesday, 25-Jul-2023 21:00:33 JST SolSoCoG

     in reply to

     • Delta Lead

     @deltalead waaaaaait a second. I was like "okay f it, lets just browse ps aux even if its a hundred thousand pids" and I found something screaming "hey I block these ports" [Game] <defunct> :eichk4tchu: I didn't realize it would just be named Game instead of ConanSandbox.exe

     maybe ps aux | grep defunct would help next time, duh.

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     SolSoCoG (solsocog@ieji.de)'s status on Tuesday, 25-Jul-2023 21:04:51 JST SolSoCoG

     in reply to

     I've had a weak moment today. It was just a <defunct> process.

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     snort (snort@ieji.de)'s status on Wednesday, 26-Jul-2023 01:17:39 JST snort

     in reply to

     @SolSoCoG nothing with sudo sockstat?

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     oheso (oheso@ieji.de)'s status on Wednesday, 26-Jul-2023 07:38:14 JST oheso

     in reply to

     @SolSoCoG I think you're at least two layers deeper than I've ever been. Good luck!

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     SolSoCoG (solsocog@ieji.de)'s status on Wednesday, 26-Jul-2023 08:33:12 JST SolSoCoG

     in reply to

     • oheso

     @oheso yeah in the end I just had to do a px aux|grep defunct to find out I actually just had a classic zombie process to sigkill :eichkat3r_hot:

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     oheso (oheso@ieji.de)'s status on Thursday, 27-Jul-2023 06:14:20 JST oheso

     in reply to

     @SolSoCoG Glad you tracked it down.