I use 3G internet, and every time i turn off my pc, next morning i have another ip. Just checked, few days ago saved my ip address, today its different...and this still doesn't save me from flagged ip ban. So idk, it's not only jsut changing ip numbers.
Not to mention, few years ago, i had accoun that was stolen with all info. After alot of recovers acc got locked. Now, few days ago i tryed to unlock, and i sitll got error that my ip address is banned from trying recover this account...so if jagex flagged you, changing ip will not help. you need to change also all those mac addresses and so on...atleast what my expierence says..