Key takeaways
- Pi-hole works cleanly with ASUS routers when it is handed out through the LAN DHCP settings, with the router’s own IP not advertised, no second DNS server, and IPv6 DNS covered. A Raspberry Pi 4 on wired Ethernet with a reserved IP is the most…
To use Pi-hole with an ASUS router, give the Pi-hole device a fixed IP address, then enter that address as DNS Server 1 under LAN > DHCP Server in the ASUS web interface and set “Advertise router’s IP in addition to user-specified DNS” to No, so every device that gets an address from the router sends its DNS lookups to Pi-hole. Leave the router’s WAN DNS pointed at a public resolver, and handle IPv6 DNS separately or ads will slip past.
Two ways to wire Pi-hole into ASUSWRT
There are two places on an ASUS router where DNS can be changed, and they behave very differently. Picking the right one up front saves most of the troubleshooting people run into.
| Method | Where in ASUSWRT | Per-device stats in Pi-hole | Risk | Recommended? |
|---|---|---|---|---|
| LAN DHCP DNS | LAN > DHCP Server > DNS Server 1 | Yes, every client shows by name or IP | Low | Yes |
| WAN DNS | WAN > Internet Connection > DNS Server | No, all queries appear to come from the router | Can create a DNS loop if Pi-hole’s upstream is the router | Only as a last resort |
The LAN DHCP method hands Pi-hole’s address directly to clients. The WAN method makes the router itself use Pi-hole, and clients still talk to the router, which hides which device made each request.
Hardware to run Pi-hole on
Pi-hole is light. A home network with 30-60 devices generates tens of thousands of DNS queries a day, which even small single-board computers handle easily. The bigger concern is reliability: if the Pi-hole box goes down, DNS stops and the internet seems “broken” for everyone.
| Device | RAM | Network | Typical power draw | Notes |
|---|---|---|---|---|
| Raspberry Pi Zero 2 W | 512 MB | Wi-Fi only (Ethernet via USB adapter) | About 1-2 W | Cheapest; add a USB Ethernet adapter for stability |
| Raspberry Pi 4 Model B (2 GB) | 2 GB | Gigabit Ethernet | About 3-5 W | The sweet spot; room for Unbound or other services |
| Raspberry Pi 5 | 2-8 GB | Gigabit Ethernet | About 3-7 W | More than Pi-hole needs; good if it also runs other containers |
| Old mini PC or NAS with Docker | 4 GB+ | Gigabit Ethernet | About 6-15 W | Reuses existing hardware; keep it on a UPS |
Running cost example: a Raspberry Pi 4 averaging 4 W uses about 35 kWh a year (4 W x 8,760 hours). At $0.16 per kWh, that is roughly $5.60 a year. Use a quality power supply and a decent microSD card or USB SSD; cheap cards are the most common point of failure.
Step-by-step setup
1. Install Pi-hole
Flash Raspberry Pi OS Lite (64-bit) to your card, connect the Pi to the router with an Ethernet cable and enable SSH. Then run the official installer from the Pi-hole website. During setup, choose an upstream resolver such as Cloudflare or Quad9, keep the default blocklist, and note the admin password the installer shows or set your own afterwards.
2. Reserve a fixed IP on the ASUS router
In ASUSWRT, open LAN > DHCP Server, enable Manual Assignment, pick the Pi from the client list and assign an address such as 192.168.50.2. Click Apply. Reboot the Pi so it picks up the reserved address. A reservation is safer than a static IP set on the Pi, because the router will never hand that address to another device.
3. Point DHCP clients at Pi-hole
On the same LAN > DHCP Server page, enter the Pi-hole address in DNS Server 1. Leave DNS Server 2 blank: if you add a public DNS server there, devices will use it whenever they like, bypassing filtering. Set Advertise router’s IP in addition to user-specified DNS to No. Apply.
4. Leave WAN DNS alone
Under WAN > Internet Connection, keep the router’s own DNS on your ISP or a public resolver. Pi-hole needs a working upstream path, and the router needs DNS for firmware checks and time sync even if Pi-hole is offline.
5. Handle IPv6
If IPv6 is enabled under IPv6 in ASUSWRT, the router may advertise its own IPv6 DNS, and many devices prefer it. Either enter Pi-hole’s IPv6 address in the IPv6 LAN DNS field, or disable IPv6 on the router if your ISP does not require it. Skipping this step is the single most common reason ads still appear.
6. Renew leases and confirm it works
Devices keep their old DNS settings until their DHCP lease renews. Reconnect Wi-Fi on phones, or run ipconfig /renew on Windows. Then open the Pi-hole dashboard and confirm queries are arriving from individual client addresses.
Stopping devices that ignore your DNS
Some smart TVs, streaming sticks and apps use hard-coded DNS servers and never ask Pi-hole. Recent ASUSWRT firmware on many models includes DNS Director under the LAN section, which can redirect all DNS traffic from clients to a chosen server. Set a custom DNS entry with Pi-hole’s address and apply it globally, then exclude the Pi-hole itself so it can still reach its upstream. Devices using encrypted DNS over HTTPS can still bypass this; Pi-hole’s default blocklists and browser settings help with that.
Common problems and fixes
| Symptom | Likely cause | Fix |
|---|---|---|
| All queries show the router’s IP | Pi-hole set as WAN DNS instead of LAN DHCP DNS | Move it to LAN > DHCP Server > DNS Server 1 |
| Ads still show on some devices | IPv6 DNS or a second DNS server leaking | Fix IPv6 DNS, clear DNS Server 2 |
| Whole house loses internet occasionally | Pi-hole box rebooted or SD card failing | Use a reliable power supply and SSD, or run a second Pi-hole |
| Local device names do not resolve | Pi-hole has no view of router DHCP names | Enable conditional forwarding in Pi-hole to the router’s IP |
| A site or app breaks | Over-aggressive blocklist entry | Check the query log and allowlist the domain |
Which ASUS routers this applies to
The menus above apply to ASUSWRT on current RT-AX and RT-BE routers as well as ZenWiFi mesh systems, where settings are applied from the primary node and pushed to satellites. On mesh setups, make sure Pi-hole is wired to the main router or to a wired backhaul node to keep DNS latency low.
Bottom line
Pi-hole works cleanly with ASUS routers when it is handed out through the LAN DHCP settings, with the router’s own IP not advertised, no second DNS server, and IPv6 DNS covered. A Raspberry Pi 4 on wired Ethernet with a reserved IP is the most practical hardware choice, and DNS Director closes the gap for devices that try to go around it.
