Setting up Pi-Hole on Asus router

[jfb]

Your debug log shows no problems with the Pi-Hole, so this is a router issue.

@gordon

I set the LAN DNS to the IP address of my RPi I cannot access my router anymore

There are typically some DNS settings in the WAN interface section. For example, from the manual for an ASUS AC68R router (might not be your model), there is a WAN option to connect to DNS server automatically. This should be deselected, as your DNS server is on your LAN.

Also on the WAN, there is an option for Dynamic DNS - this should be disabled.

Also look for other options such as DNS pre-binding (disable that).

A better option might be to use the Pi-Hole as the DHCP server. When the clients get their lease from the Pi-Hole, they will be assigned the Pi-Hole as their DNS server. There are other advantages to using Pi-Hole as DHCP as discussed here:

How do I use Pi-hole's built in DHCP server (and why would I want to)?

Using Your Existing Router For Network-wide Ad Blocking You might not need to use Pi-hole's DHCP server: In many home environments, your router also functions as your DHCP server. In this case, you can often set Pi-hole to be the DNS server for your network clients in the router's DHCP (or LAN) settings page, which allows all of your network clients to block ads simply by connecting to the network. Setting it up this way is also what makes Pi-hole very powerful for network-wide ad blocking. …