Sharing our internet connection through my switch

[JCROCCO]

I have a business network and it includes a managed Netgear Switch GS724T. We want to share our internet connection only, but no other ability, to our neighboring business next door. We have a T1 and they are actually our tenant next door, but since it is a short lease, they cant get internet access affordably.

I would like to give them a port on our switch to give the internet access only, but prevent them from accessing other computers, NAS devices, printers, etc.

Is this fairly easy to do? Any helpful advice would be appreciated.

EDIT:
I looked into using the V-lan, and I tested it. It seems if I take an existing computer port and the router port, and put them in another v-lan, and take the computer port out of the default v-lan, it allowed me to access the internet only, and nothing else. Is this correct way to do it? If so, it seemed too easy, thus my reason for asking.

 

[imagoon]

I would be surprised if they could access the internet at all. All a vlan does is divide up a switch simulating multiple switches. Each vlan would need its own path to the Internet. You could split the access at the router with careful configuration (assuming a good router here) or a policy based firewall.

The fact that it 'just worked' when you changed the vlan the port was exporting would make me nervous.

-EDIT-

If I am reading that correctly.. your moving both the router and one pc port to a new vlan. That makes sense why it would work... you just moved your entire internet connection to a 'separate switch'. Highly unlikely that your network (the rest of your gear in the other vlan) has internet access when you do that.

 

[JCROCCO]

Thats what I thought, but the vlan allows ports to be in multiple configurations. It did seem to work, but seemed too easy, so I am questioned it.

I removed the port for the computer from the default vlan, but not the port for the router. I created a new vlan with the port I deleted from the default, and added the routers port. So the new vlan only had the one computer port and the router port.

Seemed to work. I may test it again to make sure others dont lose internet, but it didnt seem so.