So I have an ASUS router just sat around doing nothing, but with sky you simply cannot swap the router as their network does not allow you for some strange reason.
So how would I go about swapping the router? I am on fibre optic and I have the fibre box in the front room next to the phone in line, will this allow an ADSL router or cable?
Youre on a fiberoptic network and you want to replace the modem with an ADSL (phone line) modem, that right there is your problem. Its not strange that sky would lock you into their hardware, its a basic kind of security measure, if only certain authorized modems are allowed on the ISPs network it means they can have a lot more control over your internet while simultaneously blocking any would be freeloaders. There was a fairly substantial cable modem hacking thing going on for a long time in the states where all you had to do if you wanted free internet was modify the firmware certain cable modems and you could get online. http://arstechnica.com/tech-policy/2012/06/29/how-the-angel-helped-15000-people-steal-broadband/ I'd say this kind of thing is why ISPs around the world take a "our hardware or none" policy even though they don't have any legitimate technical reasons, plus it means they can ask for the modem back and give it to new customers without having to buy as many new modems.
Now if you want to make use of the ASUS modem as a eithernet/wifi router on your local network you can but you'll have to do some basic stuff like decide which modem is going to have the DHCP server (automatic local network IP setup) and of course the Sky modem will have to be the gateway for your network. It would take an afternoons worth of youtubing to learn how to do this but most networking hardware follow a "prescribed" way of doing things so its relatively straight forward once you learn what you are looking for.
Technically it is possible to replace any ISP given device. When using fibre, you simply can't swap the modem due to the variance in fibre technology.
If you are literally on about the router (aka it has a WAN port that passes to a modem) there is no reason why you can not replace it. However, what is likely going on is that Sky have a backdoor into their routers for cough service reasons cough and changing the router out will likely stop them from being able to provide troubleshooting from their end.
Anyway, we need some clearer idea on what you want to change. Is it the bit where fibre terminates and changes to Ethernet (aka the modem) or the device on the end of the ethernet cable (router).
Okay I managed to find the exact router, turns out its cable not ADSL.
Anyways its a Asus RT-N56U router, the closest connection type I can get is LAN, and even for that its not a simple drop in replacement.
I remember hearing about DD-WRT replacement for it and then setting it up that way, but it required Wireshark to actually find out certain things on the network, and when I actually got the router the firmware was not around anymore
You could always do this setup...
WAN <-> ISP HARDWARE <-> ISP LAN <-> YOUR ROUTER <-> LAN <-> YOUR DEVICES
My setup is something similar.
I used to have a setup like that on my old ISP so I could run the PC, XBox and other devices wired.