If your connecting by IP your DNS server is not an issue I would think. I have never heard of your router but some routers use a non standard port for management access and they can also be set to allow only 443 or HTTPS. Your routers IP is probably your default gateway. So from a cmd line type ipconfig and hit enter. If your gateway is the 192.168.1.1 then you have the right address, try https://192.168.1.1 and also look in the router manual to see if they use a non standard port i.e. 192.168.1.1:56000
you may also try rebooting the router. It couldbe that the http service is hosed.