Arch Linux

Rhizotome

Member

Registered: 2017-11-20

Posts: 17

[SOLVED] Ethernet connecting and disconnecting instantly.

When I plug my ethernet cable, the network indicator briefly shows on then off.
When I try to restart dhcpcd with "dhcpcd - k & & dhcpcd", it loops at :
enp37s0: soliciting a DHCP lease
enp37s0: offered 10.188.209.202 from 10.188.0.1
enp37s0: probing address 10.188.209.202/16
02:**:**:**:**:**:**(**:**:**:**:**:**) claims 10.188.209.202
enp37s0: DAD detected 10.188.209.202
enp37s0: solliciting a DHCP lease
Etc.
Sorry for the poor formatting, but I'm doing this quickly on my phone and I don't really know how to format logs.
Thank you for your help

Last edited by Rhizotome (2021-05-09 07:41:42)

seth

Member

Registered: 2012-09-03

Posts: 51,227

Re: [SOLVED] Ethernet connecting and disconnecting instantly.

Is this on the isntalled system or w/ the installation iso?

Sanity check:

find /etc/systemd -type l -exec test -f {} \; -print

Also sanity check: is this a rasperry pi (where this problem is pretty common)?

You can psot that and a the actual looping output as link to an image (photo w/ your phone) if you have not other means to get the system online.
(The obfuscated stuff should™ be a MAC - that's not really private data)

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Rhizotome

Member

Registered: 2017-11-20

Posts: 17

Re: [SOLVED] Ethernet connecting and disconnecting instantly.

Thanks for the reply. It's a normal desktop with a full installation that was functional for a while before.
For the sanity check :

Then the output of sudo dhcpcd -k && sudo dhcpcd :
.
Finally when I typed USB cable in the original message I meant ethernet cable. I've corrected it, and I was not really trying to obfuscate but just didn't want to type these long strings of characters. Thanks again for taking the time to help.

Last edited by Rhizotome (2021-05-08 21:03:17)

seth

Member

Registered: 2012-09-03

Posts: 51,227

Re: [SOLVED] Ethernet connecting and disconnecting instantly.

link to an image

The board has a 200x200 limit rule.

On topic: you've dhcpcd AND networkmanager enabled -they'll get into a race and trip over each other. That's a common problem for users who didn't read the network installation part closely enough
=> Pick one and stop-disable the other. There *might* be a subsequent problem, but this is the first obstacle.

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How to upload text · How to boot w/o GUI · Disable Windows Fast-Start! · Fix your xinitrc

Rhizotome

Member

Registered: 2017-11-20

Posts: 17

Re: [SOLVED] Ethernet connecting and disconnecting instantly.

Sorry for the images. It's very possible I didn't read close enough at installation, or that I messed up later. The outputs of the two commands stay roughly the same though after disabling (except for the lines about network manager in the first since I've disabled it).

seth

Member

Registered: 2012-09-03

Posts: 51,227

Re: [SOLVED] Ethernet connecting and disconnecting instantly.

Did you only disable or also stop them (in doubt rebooted)?

In case of the latter try

sudo ip neigh flush all

and if the issue remains post your dhcpcd.conf

Also rather stop the dhcpcd service than killing before restarting it.

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How to upload text · How to boot w/o GUI · Disable Windows Fast-Start! · Fix your xinitrc

Rhizotome

Member

Registered: 2017-11-20

Posts: 17

Re: [SOLVED] Ethernet connecting and disconnecting instantly.

I both stopped and then disabled and rebooted. The command didn't solve the issue, so here's my dhcpcd.conf :
hostname
duid
persistent
option rapid_commit
option domain_name_servers, domain_name, domain_search, host_name
option classless_static_routes
option interface_mtu
require dhcp_server_identifier
slaac private
noipv4ll
interface wlp36s0
static domain_search=aieu

(200p images are really hard to read)

seth

Member

Registered: 2012-09-03

Posts: 51,227

Re: [SOLVED] Ethernet connecting and disconnecting instantly.

You can try to switch to clientid, but also reboot the dhcp server (likely your router)

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How to upload text · How to boot w/o GUI · Disable Windows Fast-Start! · Fix your xinitrc

Rhizotome

Member

Registered: 2017-11-20

Posts: 17

Re: [SOLVED] Ethernet connecting and disconnecting instantly.

I've tried using network manager instead and it works, so it was probably as you thought something to do with dhcpcd conf. Thanks à lot for the help.