[Adhij]

Hi

I'm sharing my internet connection with a bunch of people in the same building through a router (I'm the one who actually pay for it). Recently, I found out that one of them has been sucking up all my bandwidth, made my internet very slow. I decided to change my router setting, using maximum upload and maximum download speed setting for the culprit's MAC Address.. But it didn't work. Finally, I can't stand it anymore, so I'm denying his MAC Address thus making him unable to use my internet completely.

After I denied his MAC Address, some unfamiliar IP Address appear in my router's active session list.
Note that my router setting use 192.168.9.xxx so I assume all user must be given 192.168.9.xxx IP's..
then where are these 192.168.2.xxx, 192.168.1.xxx, or 172.xxx.x.xxx IP's coming from? (see the picture)

I'm suggesting that someone is using an illegal program that produce multiple IP's to connect to my router. Probably, that's the reason my maximum upload/download router setting didn't work out.
Can someone explain to me (1) where are those unrecognized IP's coming from?
(2) what kind of program is it?
(3) is there anyway I can still share my internet connection with the culprit without risking my internet speed?

Thank you and sorry for my poor english.