At one end, it can route between virtual SDN or VNET segments in a lab. At the other end, it can boot a small physical mini PC from a live ISO, save its configuration on USB, buffer logs in RAM, and become a persistent home router without installing an operating system to an internal disk.

That range is the point. Real routers are not just packet forwarding. They are DHCP, DNS, prefix delegation, tunnels, NAT, firewall policy, health checks, logs, service units, sysctl values, and recovery behavior. routerd keeps those parts in one typed resource graph.

Why a diskless router?​

Small N100 or NUC-like PCs are good router hardware. They are fast enough for a serious home network, inexpensive, and easy to replace. But many users do not want another full Linux installation to maintain.

The routerd live ISO gives you a middle ground:

• boot from ISO
• answer a text wizard
• store router.yaml on a USB stick
• keep logs in tmpfs
• flush compressed logs and state to USB once per day
• reboot back into the same router state

It is close to an appliance experience, but the source of truth is still a normal YAML file you can read, copy, and version.

Try it in Proxmox VE first​

The same ISO works well as a lab VM. Create a VM with one WAN NIC and one isolated LAN NIC, mount routerd-live.iso, and use the serial console:

qm create 200 \
  --name routerd-live-demo \
  --memory 1536 \
  --cores 2 \
  --ostype l26 \
  --serial0 socket \
  --vga serial0 \
  --boot order=ide2 \
  --ide2 local:iso/routerd-live.iso,media=cdrom \
  --net0 virtio,bridge=vmbr0 \
  --net1 virtio,bridge=vmbr490
qm start 200
qm terminal 200

The wizard runs on both framebuffer and serial consoles:

Persist only what matters​

When you enable USB persistence, routerd writes this small layout to the USB partition:

routerd/
  router.yaml
  logs/
  state/

The live helper detects ext4, vfat, and exfat, mounts with async,noatime by default, and uses Alpine lbu to preserve selected local state.

Check the result​

After the wizard applies the generated config, routerctl status should report a healthy router:

Then attach a LAN client and check DNS plus outbound HTTPS:

For the full step-by-step guide, see Diskless mini PC walkthrough.