Fix for Docker Breaking KVM Networking

Detailed on the ArchWiki below is a solution to an issue I was having when I tried to use a network bridge br0 alongside Docker on my server.

The solution that I thought worked initially was to add the below to /etc/docker/daemon.json. This got the bridge working for virtual machines, but broke Docker container external connectivity (containers couldn’t access the internet).

{
  "bridge": "br0"
}

In the end I needed to run the iptables rule instead, and that got things working for both Docker and the Virtual Machines.

iptables -I FORWARD -i br0 -o br0 -j ACCEPT

About

I'm a technology professional who's been passionate about computers since my Grandad introduced me to an Intel 386 back in the 90s when I was a kid. Those moments inspired a passion within for technology, and I've been playing around with anything with a circuit board ever since. Whenever I have a moment you can probably find me working on something computer-related, and this is where I like to write about those moments.