Own Your Home Network: DNS and DHCP on a Small Box

Own the quiet jobs first

Your router already handles name lookup (DNS) and address assignment (DHCP). You can move those jobs to a small box you keep, without renting basic network behavior or becoming a full-time admin.

A DNS server on the local network can answer lookups an order of magnitude faster than a remote DNS server. That speed is useful, but ownership is the bigger win.

Home DNS setups can use the no-cost open-source projects Pi-hole and AdGuard Home. A Raspberry Pi consumes 30 watts or less, while typical servers can draw hundreds of watts. In one home-lab deployment, AdGuard Home used 50 MB of RAM from a 512 GB allocation and 2 GB of storage for DNS caching and logs. That footprint fits a shelf, a closet, or a corner of a desk.

The margin is in not babysitting it. The box can answer names and hand out addresses while you do other things. Count the hours you spend watching it, not the price you paid. Keep the setup boring enough that you only think about it when something changes.

The five-point ownership checklist takes one afternoon

• Choose a low-power box that can sit near the router, stay cool, and survive a power blip without becoming a project. Look for a quiet device with a network cable, a reliable power supply, and enough storage for logs. A box that runs warm is a box you will move. A box that needs a special cable is a box you will forget. Pick one you can leave on as a spare.
• Install AdGuard Home. Set an admin password, choose a stable upstream DNS service, and make sure the dashboard opens from a phone or laptop. That upstream choice matters because the local box still needs somewhere to ask when it does not know an answer. Do not point devices at the box until the upstream DNS service is set.
• Enable DHCP on the box and set the address range your devices will receive. AdGuard Home includes a built-in DHCP server alongside ad and tracker blocking. Reserve a fixed address for the box itself, so the dashboard does not wander. Keep the range away from any static addresses you already use for printers, cameras, or other devices. Turn off the router's DHCP before you hand out addresses from the box, or devices may get conflicting settings. New devices should get an address from your box instead of the router.
• Point devices to the box's DNS address, either through the DHCP settings or manually on a phone or laptop. For devices you use often, manual settings can make the change obvious. A laptop is a good early test because you can see the change immediately. A stubborn device may need a factory reset if it clings to old settings. A device should use your box for name lookup instead of the ISP's remote service.
• Verify local resolution, leases, records, and fallback when the ISP is down. Create a test record, check the lease list, and disconnect the upstream connection briefly to see whether local names still resolve. A local record is a name you define yourself, such as a printer or a home server. You are finished when a local name resolves, the lease list shows connected devices, and fallback works when the upstream connection drops.

Keep the box boring after setup

ISC's isc-dhcp-server package stopped being maintained in 2022. As of October 2024, ISC's repository offered Kea 2.6.1, with features absent from the 2.4.1 stable branch. Prefer a maintained app that bundles the jobs you need. Keep the box on a stable power source, export the configuration after changes, and check the dashboard after a reboot. A small log file is useful; a full disk is a problem. Review the log size now and again, and store the exported copy somewhere you can find it.

Start with the dashboard, not the router. If a device cannot reach the internet, check whether it has a lease, whether the upstream DNS is reachable, and whether the local record you expect is present. If the dashboard is reachable but the internet is not, the box may be doing its job while the upstream path is broken. If the dashboard is not reachable, check power, cable, and the device's own network settings before you touch DNS.