Building a Complete Home Lab Using Just a Laptop (Proxmox + OpenWRT Setup)

You don’t need a server rack or expensive hardware to start a homelab.
With a single laptop, you can build a complete, portable lab running Proxmox and OpenWRT, with Wi-Fi passthrough and Multi-WAN failover.

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Why Use a Laptop?

• Portable, silent, and power-efficient
• Built-in UPS (battery)
• Perfect for learning, testing, and travel
• Combines Wi-Fi + Ethernet for redundancy

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Step 1 – Install Proxmox VE and a Desktop Environment

1. Create a Proxmox USB installer and boot your laptop.
2. Install Proxmox VE 9 and set a static IP.

3. Enable IOMMU for passthrough in /etc/default/grub:

   GRUB_CMDLINE_LINUX_DEFAULT="quiet intel_iommu=on iommu=pt"
   

   (for AMD use amd_iommu=on)

   update-grub
   

4. Edit /etc/modules and ensure these lines exist:

    vfio
    vfio_iommu_type1
    vfio_pci
    vfio_virqfd

1. Install a simple desktop for local control:

   apt install mate chromium lightdm -y
   adduser yourusername
   systemctl start lightdm
   

2. Log in and open in Chromium https://127.0.0.1:8006, your laptop now acts as both host and management station.

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Step 2 - Create the OpenWRT VM

Now that Proxmox is ready, let’s build our virtual router.

1. Create a new VM
   • Give it 1–2 vCPUs and at least 512 MB RAM.\
   • Add two network adapters:
     • net0 → WAN (bridged to your external network, e.g. vmbr0)\
     • net1 → LAN (bridged to your internal network, e.g. vmbr1)
2. Attach the OpenWRT ISO and start the installation.
   • You can download the x86-64 combined-ext4 image from openwrt.org.\
   • Once booted, assign net0 as WAN and net1 as LAN.
3. Passthrough the laptop’s Wi-Fi adapter so OpenWRT can use it as an additional WAN link.
4. Install required packages in the OpenWRT VM:

   opkg update
   opkg install kmod-iwlwifi iwlwifi-firmware-iwl7265d wireless-tools wpad-basic
   

   You can find out your Wi-Fi module and drivers in the Troubleshooting Wi-Fi Passthrough steps.

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Troubleshooting Wi-Fi Passthrough

If the Wi-Fi card doesn’t appear in OpenWRT after PCI or USB passthrough,
it usually means the Proxmox host is still “owning” the device through its driver.
You’ll need to unbind or blacklist that driver so the VM can claim it.

Step 1: Identify the device

Run on the Proxmox host:

lspci -nn | grep -i wireless

Example output

03:00.0 Network controller [0280]: Intel Corporation Wi-Fi 6 AX200 [8086:2723]

→ The PCI ID is 8086:2723 → The device path is 0000:03:00.0

Step 2: Check which driver is loaded

lspci -k -s 03:00.0

Example

Kernel driver in use: iwlwifi

Step 3: Blacklist the driver on the host

echo "blacklist iwlwifi" > /etc/modprobe.d/blacklist-wifi.conf
update-initramfs -u -k all
reboot

After reboot, the Wi-Fi adapter will no longer load on the host and can be safely assigned to your OpenWRT VM as a PCI device.

Once booted again, OpenWRT should detect the interface (e.g. wlan0). You can then connect it to your local or public Wi-Fi network as the WAN interface

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Step 3 - Build the Internal Network

1. Use only vmbr0 as your main bridge, it handles both WAN and LAN (via VLAN tags).
2. Create a VLAN 999 sub-interface on the host:

   auto enp0s31f6.999
   iface enp0s31f6.999 inet static
       address 192.168.99.10/24
       vlan-raw-device enp0s31f6
   

   This gives your Proxmox host direct access to the OpenWRT LAN.

3. In the OpenWRT VM:
   • WAN NIC → attached to vmbr0 (untagged, DHCP from your upstream)
   • LAN NIC → attached to vmbr0 with VLAN tag 999 4 Any additional VMs can join the LAN by attaching to vmbr0 and setting VLAN tag 999 in their network settings.

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Step 4 — Add Multi-WAN Failover (Optimized)

Inside OpenWRT, configure:

1. WAN → the wired NIC (attached to vmbr0, untagged, DHCP from upstream).
2. WWAN → the Wi-Fi interface (station mode, connects to another network).
3. Install the failover manager:

   opkg update && opkg install mwan3 luci-app-mwan3
   

4. Edit /etc/config/mwan3 (or use LuCI → Network → Load Balancing) to prioritize Ethernet and use Wi-Fi as backup:

   config member 'wan_main'
       option interface 'wan'
       option metric '1'
       
   config member 'wwan_backup'
       option interface 'wwan'
       option metric '2'
       
   config policy 'failover'
       list use_member 'wan_main'
       list use_member 'wwan_backup'
       
   config rule 'default_rule'
       option dest_ip '0.0.0.0/0'
       option use_policy 'failover'
   

5. Enable and start the service:

   /etc/init.d/mwan3 enable
   /etc/init.d/mwan3 restart
   

6. Test failover: Unplug the Ethernet cable and the traffic should automatically switch to Wi-Fi. Plug it back in and the routes revert to wired WAN (higher priority).