I have just decided to play with installing VM (virtual machines) on my Router hardware (2023-01). I have been reluctant to do this for a number of reasons. My separate listing for Router Hardware. Basically the machine is a bit old slow and under powered. Still basically adequate for what it does. I do not run a desktop on this machine, CLI (Command Line Interface only). The main services I am currently running on this machine are, all bare metal:

• Network configuration (of 4 x 1 GB/s ethernet ports)
  • Access to public internet modem, via 1 Ethernet port - the WAN (Wide Area Network) connection
    • modem is VDSL based, set into bridge mode to allow connection to control using this machine as router
      • modem is currently set to use direct remote DHCP/IP as specified by ISP (Internet Service Provider requirements), was originally setup using PPPoE.
      • There is also as separate static IP address setup to access and control the modem
  • A bridge network setup on the remaining 3 Ethernet ports as a LAN (Local Area Network). The bridge network setup has the following required features:
    • It allows connections of multiple physical Ethernet ports to a bridge interface device, with the bridge effectively acting as a network switch for the connected physical ports. (On my home server I have 4 x 1GB/s Ethernet ports and an add in PCIe card that provided a 2.5GB/s Ethernet port. All these physical ports are connected to a common network bridge device. This seem to just work, and each physical device seems to operate at its specific capacity.)
    • It allows connections of multiple virtual Ethernet ports to the bridge device. This is a commonly used feature on VMs and container system to obtain host system LAN and WAN access.
• ssh (for remote CLI access)
• Router software, using NFTables, with following features:
  • Firewall
  • NAT (Network Address Translation)
  • Port forwarding to basic services
    • Main public HTML sever
    • Mail server
    • VPN server (Wireguard) for remote public access.
  • Rate limiting certain IP address ranges to public interface
  • Parental control (time limiting access to public interface on certain IP addresses
• Main LAN (Local Area Network) DNS/DHCP), these services work together
  • Main local DNS server using ISC Bind9
  • Main local DHCP server using ISC DHCP

My preference would be to get a container system functioning directly on the bare metal, but Docker's use of IPtables rules on its Host would impair my Router NFTables setup. Use of a VM isolates Docker's IPTable manipulations from the main system.

I decided to try QEMU/KVM setup as follows:

• sudo apt install qemu qemu-system-x86 qemu-system qemu-utils libvirt-clients libvirt-daemon-system virtinst
• sudo apt install libvirt-daemon
• sudo apt install qemu-system

tldr;

• sudo apt install virt-manager ssh-askpass-gnome --no-install-recommends
• virt-manager -c 'qemu+ssh://baumkp@router.local.kptree.net/system?keyfile=id_rsa'
• sudo apt install gir1.2-spiceclientgtk-3.0

• KVM: virt-manager to connect to a remote console using qemu+ssh
• How To Set Up SSH Keys on Ubuntu 16.04