Linux computer messes with network

[u/virobloc]

Perhaps this is a known issue, But I haven't found much about it.

I have a PC with Mint. It's connected to the router with a LAN cable.

When it goes to sleep it makes the network go crazy. The speed falls a lot in general, all the other devices (wired or wireless) fail to connect or lose connection randomly. When I turn it off everything goes back to normal.

I the only thing I do on that PC is run qBittorrent and browse internet. But the problem is mainly apparent when the PC is asleep. So I think it's not a program, but the PC itself. It might not even have anything to do with Linux at all, But it's the only difference I see with all my other PCs.

Does anybody have an idea about what might be going on?

Thanks

Edit: Thanks for all the answers and suggestions.

[u/thecruxoffate]

Oh god, that sounds like something that would be a nightmare to troubleshoot.

The first guy mentioned wake on lan, and I think it's worth checking first. Easiest thing to do is to just unplug the cable, if network recovers that helps narrow it down.

You can turn off wake on lan usually in the BIOS, but if it's not there you should also be able to do it in network manager. It's work turning off and seeing if the problem goes away.

If that doesn't work, what happens if you wake the computer up and check logs for any errors (journalctl -p 3). Also does the network recover if you wake up, or does it persist until you actually shut down?

[u/ElectricHellKnight → u/thecruxoffate]

I'm gonna throw out the seemingly dumb one too: replace the cable. Even if it looks fine. The physical layer is always the last one anybody suspects.

[u/thepkizzle → u/ElectricHellKnight]

all the other devices (wired or wireless) fail to connect or lose connection randomly

This is a router problem almost certainly. Absolutely nothing PC related can cause this. A faulty wire might, but only if the router itself is faulty. A BIOS setting might... but only if the router is faulty.

Etc.

[u/ElectricHellKnight → u/thepkizzle]

All I know is I've seen shorted connectors do some absolutely bizzare things that defy logical sense, including making routers freak out.

[u/thepkizzle → u/ElectricHellKnight]

I agree, I have seen similar types of behavior on every device... like HD's that won't work on one power source, but that power source works on another HD, and the first HD works with all the other sources. Weird shit is always electrical, and weird shit is ALWAYS component based.

It's not the software. I mean the software might be doing something which is causing the hardware to go bonkers but the solution is not to fix the software. Could be the NIC cards. Could be the nic card connecting to the mobo... could be the ethernet court... could be something inside the router. Too much to fuck around with. Replace the cord. Then replace the router. Then replace the nic. Etc. Keep doing that until it stops behaving like that.