Arch Linux

Xisah

Member

Registered: 2021-06-03

Posts: 6

[SOLVED] Wifi connection works, but Ethernet doesn’t

Hi.

This is my first post in the Arch forum & I’m a bit of a noob so please bare that in mind. I’m also posting from my mobile device as I’m currently installing Arch Linux on my laptop, which is a Lenovo Thinkpad x250. I will try to provide as much information as I can type out but I won’t be able to copy & paste huge walls of text.

After installing the ISO onto a flash drive I have plugged it into my laptop & have been trying to configure the network. I have been following the amazing Arch Wiki as much as I can but I may have missed something along the way.

Prior to explaining my situation, I’ve noticed that my wifi interface is defaulted to wlan0, however my Ethernet interface has changed to enp0s25. I’m not sure if this is supposed to happen, but it’s something I’ve noticed.

My Ethernet driver is listed and enabled, as when I type

ip link

I get

enp0s25: <BROADCAST,MULTICAST,UP,LOWER_UP>

My cable is definitely plugged into both my router & my laptop.

An IP address has been set up for the Ethernet, as when I type

ip address show | grep enp0s25

I get I am shown the default IP address for my router.

The routing address for enp0s25 is set up. I have tried adding a route and I am told that the file already exists, so I haven’t played around much with the routing.

I can also ping my local network with the default gateway, and I’m also able to ping 8.8.8.8 with 0% packet loss - however I cannot ping domain names such as archlinux.org or google.com. If I do try to do this, I am given a message ‘Destination unreachable: Address unreachable’.

When I unplug my Ethernet cable and try to use the wifi that I’ve set up, I get full network connection & im able to ping my local network, 8.8.8.8 & domains such as archlinux.org & google.com.

If there is an issue, and a way to get both Ethernet & wifi running I’d rather resolve this before continuing. I have looked at the Arch Wiki for advice & have looked through the forums but cannot seem to fix the issue.

Any help is greatly appreciated, thank you in advance.

Last edited by Xisah (2021-06-05 06:56:44)

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,415

Re: [SOLVED] Wifi connection works, but Ethernet doesn’t

What method / software are you using to configure and manage your networks?

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Xisah

Member

Registered: 2021-06-03

Posts: 6

Re: [SOLVED] Wifi connection works, but Ethernet doesn’t

What method / software are you using to configure and manage your networks?

I believe it’s iwd - but I’m not entirely sure. I haven’t downloaded anything via pacman as of yet.

loqs

Member

Registered: 2014-03-06

Posts: 18,470

Re: [SOLVED] Wifi connection works, but Ethernet doesn’t

Compare /etc/resolv.conf when connected using WiFi vs ethernet.
What is the output of

find /etc/systemd -name \*.service -type l -a -xtype f -printf %f\\n

Scimmia

Fellow

Registered: 2012-09-01

Posts: 12,868

Re: [SOLVED] Wifi connection works, but Ethernet doesn’t

To be clear, this is while you're still on the ISO, right? Which one?

Last edited by Scimmia (2021-06-03 16:17:01)

Xisah

Member

Registered: 2021-06-03

Posts: 6

Re: [SOLVED] Wifi connection works, but Ethernet doesn’t

Compare /etc/resolv.conf when connected using WiFi vs ethernet.
What is the output of

find /etc/systemd -name \*.service -type l -a -xtype f -printf %f\\n

The output of this command, is:

cloud-config.service
cloud-final.service 
cloud-init-local.service
cloud-init.service
dbus-org.freedesktop.ModemManager1.service
dbus-org.freedesktop.network1.service
dbus-org.freedesktop.resolve1.service
getty@tty1.service 
ModemManager.service
choose-mirror.service 
iwd.service
livecd-talk.service
pacman-init.service 
qemu-guest-agent.service
reflector.service
sshd.service
systemd-networkd.service
systemd-resolved.service
vboxservice.service
dhcpcd@enp0s25.service
systemd-networkd-wait-online.service
livecd-alsa-unmuter.service

Xisah

Member

Registered: 2021-06-03

Posts: 6

Re: [SOLVED] Wifi connection works, but Ethernet doesn’t

To be clear, this is while you're still on the ISO, right? Which one?

Yes I believe so, I’m still running as root@archiso  from my USB flash drive.

It’s “archlinux-2021.06.01-x86_64.iso” from the University of Kent UK MIRROR service

Last edited by Xisah (2021-06-03 16:37:53)

loqs

Member

Registered: 2014-03-06

Posts: 18,470

Re: [SOLVED] Wifi connection works, but Ethernet doesn’t

Is the ethernet interface using DHCP provided by:

dhcpcd@enp0s25.service

in which case it would appear to not be acquiring DNS server entries when it obtains an IP address.
If you instead have assigned a static IP address for the ethernet interface.  Did you also assign DNS servers?

Xisah

Member

Registered: 2021-06-03

Posts: 6

Re: [SOLVED] Wifi connection works, but Ethernet doesn’t

Is the ethernet interface using DHCP provided by:

dhcpcd@enp0s25.service

in which case it would appear to not be acquiring DNS server entries when it obtains an IP address.
If you instead have assigned a static IP address for the ethernet interface.  Did you also assign DNS servers?

Yes I believe so. I used

systemctl enable dhcpcd@enp0s25

I was aiming to set a dynamic IP address as it’s my home router, I assume that’s what’s required.

Scimmia

Fellow

Registered: 2012-09-01

Posts: 12,868

Re: [SOLVED] Wifi connection works, but Ethernet doesn’t

To be clear, this is while you're still on the ISO, right? Which one?

Yes I believe so, I’m still running as root@archiso  from my USB flash drive.

It’s “archlinux-2021.06.01-x86_64.iso” from the University of Kent UK MIRROR service

Ok then, it will be using systemd-networkd and systemd-resolved in that case. You should not be messing with dhcpcd without stopping networks, but enabling it does nothing on the ISO anyway. You need to be checking resolved to see what it's got for DNS.

Xisah

Member

Registered: 2021-06-03

Posts: 6

Re: [SOLVED] Wifi connection works, but Ethernet doesn’t

To be clear, this is while you're still on the ISO, right? Which one?

Yes I believe so, I’m still running as root@archiso  from my USB flash drive.

It’s “archlinux-2021.06.01-x86_64.iso” from the University of Kent UK MIRROR service

Ok then, it will be using systemd-networkd and systemd-resolved in that case. You should not be messing with dhcpcd without stopping networks, but enabling it does nothing on the ISO anyway. You need to be checking resolved to see what it's got for DNS.

This seemed to have fixed the issue for now. I deleted all addresses associated with enp0s25 & proceeded with

systemctl enable systemd-networkd

And then

systemctl enable systemd-resolved

Now I have a solid network connecting through Ethernet & WiFi.

Thank you for your help!