I'm working on a project whilst in lockdown in England, and I am hoping someone can offer some advice?

I have a machine with 5 physical eth interfaces on Linux Mint, 20.04. All eth interfaces communicate as expected through firewalld and the world is 'almost' roses. Eth4 is my gateway to the outside world, and eth0-3 are internals. All fine, can ping and talk to each other. Eth0-3 are bridges on a bridge port br0.

What I am aiming to do is add 1 or 2 virtual machines, with virtualbox, on to this host. Then use kernel networking with a tun or tap interface to bridge the virtual machines into the br0 interface.

I have tried all sorts of solutions over the past week, with my most successful being the vm machine getting an IP from the hosts ISC-DHCP-SERVER, but then no IP traffic going over that connection.

Can anyone please advise whether it is possible to create a virtualbox machine, and attach it to a tap or tun interface on the host, and build the tap/tun interface into the bridged br interface?

If so, a few clues would be great! I'm using this as a learning experience about the linux networking stack whilst in lockdown, but have hit a brick wall, so any help would be appreciated!

My kind regards and Thanks in advance,

Ian B

  • 2
    Why on earth would you use VirtualBox? KVM is all around much better and can just connect VMs to your bridge directly without any TUN/TAP hackery. Nov 14, 2020 at 1:03
  • Mr Hampton, thanks for a great suggestion! I am using VirtualBox because I was used to it, but it's not playing fair with my new project, so I have spent the day learning about KVM and QEMU. It's really quick, much faaster than VB, thank you for the idea. However I'm still stuck on bonding the network interface from the KVM machine to the BR0 interface on the host. It gets an IP, but then no network traffic over TCP. Any suggestion on what I'm doing wrong? Thanks man, I appriciate the help. Ian
    – Bon
    Nov 14, 2020 at 15:28


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