The only sure fire way to remove an R/D is by changing your mac address.
Log into your router, goto the clone mac address settings, pick one letter and change it to anything from A to F.
Save settings, reset your router (via unplugging the power), presto. No more RD.
As well, just changing your ip does remove the realm down, but if you do NOT switch cdkeys, you will get realm downed quicker (using the same cdkeys you just got rd'd on).
Not here to argue cause I know that's where this will head. It's just a fact. Change ip, swap cdkeys, you're good.