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Hard times with Ubuntu’s 18.04 new network configurator

After a long time i have built a new pc and have installed Ubuntu server on it. My main goal was to have a server to run remote VMs on QEMU/KVM.

I think i’ve struggled enough with it’s new network configurator: netplan

My setup have a single physical interface, and for the VM connections was necessary to configure a bridge.

I don’t know if the documentation wasn’t clear enough, or if i have misread it. I couldn’t get it to work though.

My need were:

  • be able to connect to the server through ssh
  • every VM should be able to connect to the network

The configuration down below is how i got it to work.

Network configuration file: /etc/netplan/01-netcfg.yaml

  version: 2
  renderer: networkd
      dhcp4: no
      interfaces: [enp4s0]
      dhcp4: no
      addresses: []
        addresses: [,]
          forward-delay: 0

There are some important points though:

  • You should not configure addresses to the ethernet adapter
  • You should disable dhcp on the said physical interface (as view enp4s0)
  • You shoudl configure your bridge and link it to the physical interface

You would have routing conflict otherwise. This way, your physical interface will use the address of the bridge and you should be able to ssh to it.