Ubuntu 22.04 network error

post by uj03109 on Oct 4, 2022

When I connect wi-fi, wired connection says Ethernet connection is established, but when I disconnect the wi-fi, in the settings, Ethernet connection is connected but internet connection is not work.

ex) ping facebook.com // name resolution error

I think it is name server problem, so I also modified the name server but the problem is still valid. There was no problem when using 18.04, but after changing to 22.04 it looks like this. I’ve reinstalled it about 3 times now.

is it a bug / issue or didn’t i have enough coffee?

best regards from korea

post by markd on Oct 15, 2022

You can see if a IP address is assigned with:

$ ip address show

And you can see the links and routing with:

$ ip link
and
$ ip route

To test the network you can ping a IP address directly example (googles DNS):

   $ ping -c 3 8.8.8.8

And you can see the name resolution in:

   $ cat /etc/resolv.conf

If ping works, it is likely the network configuration is no longer working.

It could be old settings or other issues. (some formats have changed).

  $ cat /etc/netplan/*

For example in the netplan ‘gateway4’ is deprecated and you should use ‘routes’ now.

For that specific example there is a write up:

netplan generate: gateway4 has been deprecated, use default routes instead - Unix & Linux Stack Exchange

Well that should give you a start of a few things to look for.

Mark