I'll run this OS tutorial quick, so you know what it means. We usually connect to the WiFi modem router via 192.168.1.1 (usually that's the case for D-link, Tp-link, Netgear, other major brands).
IP Mapping is a method where you can cloak that IP with name so you can type that name instead of IP address.
In Windows Vista, 7, 8 , run notepad with admin priviledge. Open, windows/system32/drivers/etc/hosts
In MacOSX, open terminal, type in:
sudo nano /private/etc/hosts
We will have found that #127.0.0.1 localhost is inside that.
What it means is locahost is 127.0.0.1. (do not touch this ip as this is internal machine IP).
Now, here comes the fun part. Add down below the line (Change to relative IP address on your connected network):
For Windows - hit CTRL+S (Save for Notepad)
For OSX, hit CTRL + O to writeout (not the apple key)
Next we need to flush the dns to renew it.
For windows, open comamnd, and type in: ipconfig /flushdns ,
For OSX, type dscacheutil -flushcache
Now open your browser, type "http://mymodem" - (i.e. travel to 192.168.1.1 first before hitting the internet) , so if the ip works, it will go to your modem first.
If you cannot connect via IP, this method will not work as it is only a mapping of IP address to name.
Credits: Domi (For helping me with the windows part).