There are 2 systems here:
1)
The system here is one person subscribe, then many pple pay the
person 10 euros a month to be able to connect to the net through
his router wirelessly.
2)
The whole hostel will have one internet in which everyone plugs
their computer into the lan network... sort of like within
NUS...
In both cases, I believe the IP will be the same... unless it is
possible to look into the router to see which ip address the router
assigns to at that particular pt in time