To access the administration site on my new Asus router, the documentation says to go to http://www.asusrouter.com. This worked great during initial setup. I also run AdGuard Home to block ads at the router level. This involves setting the DNS server for the router to the IP address of the machine hosting AdGuard. This also worked perfectly, but when I did this I started getting 404 errors when navigating to http://www.asusrouter.com. I suspect by default, the router is set up to route that address to itself. Setting the DNS server to a custom value overrides this behavior. We can get it back by using a DNS Rewrite in AdGuard Home.