Step by step process: 1. On a device already on that Wi‑Fi network, open a browser and go to the router’s admin page (often 192.168.1.1 or 192.168.0.1). Sign in with the existing admin credentials. 2. Open the WAN, Internet, or DHCP settings page and write down every DNS value already shown, including whether the mode is “Automatic,” “From ISP,” or a pair of addresses. Do not change the mode. 3. If a manual DNS field is present, select it, then type the same addresses you just wrote down, in the same order, with the same separators. If the field was empty and the mode was automatic, leave it empty and leave the mode automatic. 4. Open any secondary DNS, IPv6 DNS, or DNS-over-HTTPS toggle. If it was off, leave it off. If it was on, leave the existing resolver string exactly as displayed. 5. Save or apply. If the router asks to reboot, reboot, then return to the same page and confirm the mode and addresses match the notes from step 2. 6. On each phone, computer, or TV, open network settings for that Wi‑Fi network and check DNS. If it says automatic or shows the same addresses as before, leave it. If a device has a custom DNS, re-enter that same custom DNS and save. 7. For the “ad blocker” part, open the browser or app you already use. If an extension or system blocker is already installed, leave its lists, filters, and enabled state as they are. Do not add a new extension, VPN, or hosts file. 8. Restart the browser only. Load a normal page and confirm the network still uses the same gateway and the same DNS values you recorded.