I can't use wifi and Ethernet at the same time

Question

I have a problem with my Wifi and Ethernet. Let me explain what's happening.

I'm using a laptop with Ubuntu 20.04. I'm connected to the Wifi with the default configuration (right now, it's 192.168.222.107). That works without problem, I can connect to the internet and some partners that are in the same network are able to ping me.

I'm also connected via network with others laptops, using a switch. I have enabled a static IP in the network config, because we're using VirtualBox and I need a special IP-range (192.168.50.x) to work with them (we're using Ubuntu Server in the VirtualBox and we're setting up some servers). I can ping the servers and others computers using 192.168.0.x.

The problem is when I have both connections at the same time. I get disconnected from the internet. Ubuntu shows as if I'm already connected to the wifi, but with a "?" in it, and I can't visit any website. I'm also unable to install anything using "sudo apt install".

I've bean searching for a while, and I found a post here about someone having a similar problem ([this one][1]). I saw the answer, so I decided to ping 8.8.8.8 (Google's DNS akaik), and I was able to do it. But I couldn't ping google.com.

The answer said that I should install dnsmasq, so I found another useful answer ([this one][2]). I did both things, but nothing changed.

I need to use both connections at the same time, but it looks as if it's impossible. Hope anyone here can help me, and if you need more info just tell me! Thanks. [1]: Problems with ethernet and wifi [2]: https://askubuntu.com/a/1243881

Answer 1

Alright, finally I found the problem.

The VirtualBox server's IP (50.4) was the same one as the DNS server of my network. That was causing a DNS conflict, so I wasn't able to browse throw the internet. I changed the IP range (55.4) and now everything works fine.