Homelab / networking

Dedicated OPNsense router / firewall

I wanted more control over my home network than a normal consumer router gave me, so I repurposed a Dell OptiPlex 3070 SFF into a dedicated OPNsense box.

What I wanted from the build

  • A dedicated firewall instead of relying on an all-in-one consumer router.
  • Separate physical WAN and LAN interfaces.
  • Hardware that OPNsense and FreeBSD would support reliably.
  • A platform I could later use for segmentation, VPN access, logging, IDS, and other network-security projects.

Working around the hardware

The OptiPlex was a good small-form-factor base, but chassis clearance made the normal PCIe layout awkward for the NIC I wanted to use. I ended up repurposing the M.2 Key-E WLAN slot for Ethernet instead.

I chose an Intel i210-based adapter because it is well supported by FreeBSD through the igb driver. I did not want the external side of the firewall depending on a USB Ethernet adapter if I could avoid it.

WAN and LAN

I assigned the Intel i210 interface to WAN and kept the onboard Realtek interface on LAN. The Intel adapter had the cleaner FreeBSD support, so I preferred to put it on the untrusted side of the network.

Validation

  • Confirmed OPNsense detected both interfaces.
  • Checked link state and negotiation.
  • Verified the WAN interface received an address.
  • Verified LAN addressing and management access.

Where it fits in the lab

The main value of the build is control. It gives me a real network edge that I can configure, log, segment, and troubleshoot instead of treating the router as a black box. It also gives me a better base for future VPN, IDS, and traffic-analysis work.