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Re: [LUG] Continual network problems on Fedora 31

 

On 31/01/2021 16:00, Sebastian wrote:
Dear Pete,

As it happens on wifi and wired connections, it doesn't sound like
hardware either at the PC or router.
That would make sense, as on the occasions I have used a live OS image
on this PC I haven't experienced any problems.

Could there be another device grabbing the PC's IP address? I assume
when you are connected by wifi you have a different IP to wired?
Now that's something... Is there a way to find out if another PC is
taking the IP address from this computer? Other family members might
not appreciate me rushing down and typing apparently random commands
into their PCs!

I do usually have four IP address - an IPv4 and an IPv6 address for
both ethernet and wireless. This time, however, I had booted up
without the wireless adapter plugged in (to free up a USB port), and
now after plugging it in and running

nmcli device connect wlp0s29f7u2

I get

"Error: Failed to add/activate new connection: A 'wireless' setting is
required if no AP path was given."

This hasn't happened before! :( I've attached the output of various
commands just in case they are helpful.

Does the interface still report as up?
When the problem occurs, it does usually remain 'up', but sometimes it
reports as not connected.

All I can suggest is running tcpdump on the interface to see if it
is seeing any traffic after you have the problem.
I'm currently running ping to both the router and the internet in
tmux, and tcpdump -i enp2s0 -vv redirected to a file. Sod's Law: it'll
all work just fine today...

I would also try and do the debugging on the wired connection as
much as possible (might just be because I am old and still don't
totally trust wifi :))
I don't think I'm in a position to trust any networking at the current
moment :)

Cheers,

Pete
Thanks for your help :)

Best wishes,

Sebastian

PS. Newsflash from five minutes since this email was written: the
wireless connection just became connected all by itself, hence it's
appearance in the nmcli and ifconfig output!

--
- Freenode: 'seabass'
- Matrix: '@seabass:chat.weho.st'

It's not a silliness where NetworkManager thinks the other interface is live, switches, but neither is? and DHCP leases have expired so there is a cluster*** of bad scenarios all stacking up? Not that I can fathom a reason why any of this should happen, but daemons do the weirdest things.. I know wicd used to be bad for this in KDE years ago ..
Worth checking both your current IP address, and routing table to eliminate the above...

MJE/veremitz.
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