[Solved] Shared ethernet connection not working after update

Herbalist · 2024-06-10 09:35:47

I use an ethernet cable to share wifi connection from laptop to desktop via an ethernet cable.
connection is setup using network manager nm-applet.

both pcs use arch with network manager

created a new ethernet connection, IPv4 settings --- > Shared to other computers
on client IPv4 settings --- > Automatic DHCP

nmcli connection shows the ethernet connection state stuck at connecting (getting IP configuration)

edit: tried sharing internet from a windows laptop via an ethernet cable to the arch desktop, it worked instantly

Last edited by Herbalist (2024-06-24 08:45:48)

seth · 2024-06-10 14:24:05

Please don't paraphrase, https://bbs.archlinux.org/viewtopic.php?id=57855
https://wiki.archlinux.org/title/Networ … r_Ethernet
See whether there's a dhcp server responding and make sure you've dnsmasq installed.

sudo nmap --script broadcast-dhcp-discover # from the client that doesn't get a lease

Then check for dnsmasq/networkmanager errors in the sharing host if there's no dhcp response.

Herbalist · 2024-06-22 20:17:14

journalctl -fu NetworkManager
Jun 22 21:16:57 arch NetworkManager[686]: <warn>  [1719080217.2231] dnsmasq-manager: dnsmasq exited with error: Network access problem (address in use, permissions) (2)
Jun 22 21:16:57 arch NetworkManager[686]: <info>  [1719080217.2233] device (enp0s25): state change: activated -> failed (reason 'ip-config-unavailable', sys-iface-state: 'managed')
Jun 22 21:16:57 arch NetworkManager[686]: <warn>  [1719080217.2240] device (enp0s25): Activation: failed for connection 'Ethernet connection 1'
Jun 22 21:16:57 arch NetworkManager[686]: <info>  [1719080217.2251] device (enp0s25): state change: failed -> disconnected (reason 'none', sys-iface-state: 'managed')
Jun 22 21:16:57 arch NetworkManager[686]: <info>  [1719080217.2864] policy: auto-activating connection 'Ethernet connection 1' (fe8429a9-b909-4701-8c32-2cd15b6c8df6)
Jun 22 21:16:57 arch NetworkManager[686]: <info>  [1719080217.2872] device (enp0s25): Activation: starting connection 'Ethernet connection 1' (fe8429a9-b909-4701-8c32-2cd15b6c8df6)
Jun 22 21:16:57 arch NetworkManager[686]: <info>  [1719080217.2873] device (enp0s25): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed')
Jun 22 21:16:57 arch NetworkManager[686]: <info>  [1719080217.2876] device (enp0s25): state change: prepare -> config (reason 'none', sys-iface-state: 'managed')
Jun 22 21:16:57 arch NetworkManager[686]: <info>  [1719080217.2882] device (enp0s25): state change: config -> ip-config (reason 'none', sys-iface-state: 'managed')
Jun 22 21:16:57 arch NetworkManager[686]: <info>  [1719080217.4417] dnsmasq-manager: starting dnsmasq...
Jun 22 21:16:57 arch NetworkManager[686]: <info>  [1719080217.4450] device (enp0s25): state change: ip-config -> ip-check (reason 'none', sys-iface-state: 'managed')
Jun 22 21:16:57 arch NetworkManager[686]: <info>  [1719080217.4470] device (enp0s25): state change: ip-check -> secondaries (reason 'none', sys-iface-state: 'managed')
Jun 22 21:16:57 arch NetworkManager[686]: <info>  [1719080217.4473] device (enp0s25): state change: secondaries -> activated (reason 'none', sys-iface-state: 'managed')
Jun 22 21:16:57 arch NetworkManager[686]: <info>  [1719080217.4479] device (enp0s25): Activation: successful, device activated.
Jun 22 21:16:57 arch NetworkManager[4181]: dnsmasq: failed to create listening socket for 10.42.0.1: Address already in use
Jun 22 21:16:57 arch dnsmasq[4181]: failed to create listening socket for 10.42.0.1: Address already in use
Jun 22 21:16:57 arch dnsmasq[4181]: FAILED to start up
Jun 22 21:16:57 arch NetworkManager[686]: <warn>  [1719080217.4511] dnsmasq-manager: dnsmasq exited with error: Network access problem (address in use, permissions) (2)
Jun 22 21:16:57 arch NetworkManager[686]: <info>  [1719080217.4512] device (enp0s25): state change: activated -> failed (reason 'ip-config-unavailable', sys-iface-state: 'managed')

it would only work If stop dnsmasq, then reconnect to the ethernet connection

seth · 2024-06-22 22:45:17

Jun 22 21:16:57 arch dnsmasq[4181]: failed to create listening socket for 10.42.0.1: Address already in use

You do have https://wiki.archlinux.org/title/NetworkManager#dnsmasq ?

ip a
ip r
resolvectl status

And in doubt please post your complete system journal for the boot:

sudo journalctl -b | curl -F 'file=@-' 0x0.st

Edit:

it would only work If stop dnsmasq, then reconnect to the ethernet connection

The wiki wrote:

Note that NetworkManager starts its own instance of dnsmasq, independent of dnsmasq.service

Are you running a separate dnsmasq instance? Why?

Last edited by seth (2024-06-22 22:47:31)

Herbalist · 2024-06-24 08:46:57

it would only work If stop dnsmasq, then reconnect to the ethernet connection
The wiki wrote:
Note that NetworkManager starts its own instance of dnsmasq, independent of dnsmasq.service
Are you running a separate dnsmasq instance? Why?

disabling the separate instance fixed the issue, thanks seth.

Arch Linux

#1 2024-06-10 09:35:47

[Solved] Shared ethernet connection not working after update

#2 2024-06-10 14:24:05

Re: [Solved] Shared ethernet connection not working after update

#3 2024-06-22 20:17:14

Re: [Solved] Shared ethernet connection not working after update

#4 2024-06-22 22:45:17

Re: [Solved] Shared ethernet connection not working after update

#5 2024-06-24 08:46:57

Re: [Solved] Shared ethernet connection not working after update

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