I was talking with a friend and he mentioned that he was thinking about trying to set up two independant networks at home sharing an internet connection (DSL). How would someone set this up?
As sort of a guidline the networks would probably have the following properties:
>=1 computers per network
computers on each network could not see or interact with each other (no file sharing, etc)
as few routers/switches as possible, friend probably would want to be able to access them all
How many IP addresses does your ISP provide you with?
If two, the least hardware would be one switch, with modem and two PCs plugged in to it - both PCs would be independant.
If your ISP gives two IPs, but you have more than 2 PCs total, shove a router or two on the switch and connect the two networks to those.
If your ISP only gives one IP, you’ll have to replace the switch with a router. I don’t really recommend that, as consumer-grade routers tend to need a bump every now and again, and it would just introduce a lot of complexity to the process.
What’s the reason for this - does your friend have a room-mate with hardware of questionable sanitation? You could replace everything with two switches and a linux box with three NICS, but I’d have to think a lot about the iptables rules.
He has a suite in his basement and was toying with the idea of extending his internet access to it (and doesn’t want the renters to access his computers, etc).
The ISP provides 2 Dynamic IP addresses, though they do promise to keep them static if you buy an upgraded package (which my friend would probably have to do anyway).
Either static or dynamic would work fine - the routers don’t care either way.
One more low-requirement configuration occurs to me, using two routers. Router A plugs in to the modem, and is used by the renters.
Router B also plugs in to router A, and is used by your friend. He would be able to access machines on A and B, but the renters would have only A.
Configuration and troubleshooting might still be an issue - I’d prefer not to be sending packets through two routers if I can help it.
