VMs

This entry explains how I have configured a linux bridge, dnsmasq and iptables to be able to run and communicate different virtualization systems and containers on laptops running Debian GNU/Linux. I’ve used different variations of this setup for a long time with VirtualBox and KVM for the Virtual Machines and Linux-VServer, OpenVZ, LXC and lately Docker or Podman for the Containers. Required packagesI’m running Debian Sid with systemd and network-manager to configure the WiFi and Ethernet interfaces, but for the bridge I use bridge-utils with ifupdown (as I said this setup is old, I guess ifupdow2 and ifupdown-ng will work too). To start and stop the DNS and DHCP services and add NAT rules when the bridge is brought up or down I execute a script that uses: ip from iproute2 to get the network information,dnsmasq to provide the DNS and DHCP services (currently only the dnsmasq-base package is needed and it is recommended by network-manager, so it is probably installed),iptables to configure NAT (for now docker kind of forces me to keep using iptables, but at some point I’d like to move to nftables)....