(GL-AX1800) DNS for Beginners & Setup Downstream of Comtrend NL3120

I just setup the GL-AXT1800 Flint router and it's working great so far. I don't want to mess anything up as it's corrected issues I had with the Comtrend NL3120 router/gateway that my ISP provides.


  • I am using the NL3120 as the gateway with 2.5 Ghz and 5 Ghz set to "off" in the admin panel of the Comtrend NL3120 to reduce interference and completely move all wireless devices to the new AX 1800

  • Installed included Cat 6e flat cable from ETH1 of Comtrend NL3120 to WAN of GL-AX1800.

  • Setup custom WiFi SSID for 5/2.5GHz and changed password.

  • No other settings changed.

  1. If there are any suggestions on how to better configure this setup, please let me know. Not sure if the existence of the router functionality on the NL3120 upstream of the GL-AX1800 will cause issues or not. Suspect it may hinder performance, but the speeds and connectivity are now better than ever, so I don't want to mess that up.

  2. I'm wanting to ensure my DNS resolution for everything is not provided by my ISP or Google. However, I want to make sure I set this up correctly. What is the recommendation for setting this up? I'm interested in encrypted DNS, but not sure if it has the potential to cause issues anywhere.

Use case note:
I use my internet almost every day to log in to a secure VPN for work. Without that, I don't have access to most of the tools I need. So whatever I do, I don't want it to impact or interfere with the operation of this VPN on my work computer.

First of all: everything isn't possible because of various reasons. So let us continue with "mostly all DNS requests"

I would set up AdGuard Home, select some proper uplink DNS servers and select within the GL GUI: Network → DNS → Override DNS Settings of All Clients

So all unencrypted traffic will be forwarded to AdGuard Home and then forwarded to the uplink DNS you configured.

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Of course, I don't imagine anything can be 100%

Do you have any suggestion of Encryped DNS? Cloudflare? Quad9? Something else?

You can choose by yourself and based on your needs.

I go with AdGuard DNS mostly.

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Probably easiest to just set "AdGuard Home Handle Client Requests" on? Not really sure which is the fastest option with highest degree of privacy and I'd rather not break anything since I don't have time to learn it all right now.

Any advised settings for the gateway to decrease issues associated with two routers in series?