This could belong on Super User, but I thought this place was more appropiate.

I want to run Apache in my computer and want to make it available to the outside world to test a couple things. Apparently, I have to go into my router's (a TP-LINK TD 8910G) settings and forward port 80 to my PC's IP. So far so good.

Thing is, since the router uses a web based interface and it's kind of stupid, it told me that since I was using port 80 for this, I should access its settings through port 8080. Maybe it can't detect requests coming from the LAN, I don't know. Point is, now neither port can't access the configuration, and I can't access Internet. Specifically, trying to access anything (including 192.168.1.1, the router's settings) through port 80 turns up a blank page (maybe if I had the server running in my computer I'd get something, but I don't want to risk trying, I had to reset the router and restore the settings), and port 8080 gives a "Can't establish connection" error in Firefox (and similar ones in other browsers).

Is there a way to configure the router to not redirect requests coming from inside the network?

I'm a beginner with this stuff, so please try to explain in a simple way. If this is more appropiate in Super User, I'm sorry.