I'm trying to figure out a proper setup for a network at a local restaurant. They want the back office and cash registers to communicate privately and securely with each other via a wired LAN. The main back office computer needs to communicate with the internet so financial data is transmitted to the corporate office. It appears to be utilizing a dual IP address, one public and one private. The public is to allow the back office PC internet access, the private allows the registers to talk to the back office PC.

However, now they want to provide wireless internet access for their customers. Of course they want this network to be configured so it's separated from the back office and cash registers, but they also want to utilize only 1 DSL modem. I was trying to install a new wifi router for customer internet access alongside their existing DSL device but I'm having trouble.

The DSL device is providing a private network of 10.1.60.x with a 255.255.255.0 mask. This is what the cash registers & back office PC are on. Remember, the back office also has a static IP that is public (the mask is 255.255.255.252 for that connection). I'm hoping to get that removed I was trying to configure the new wifi router with a different IP range of 192.168.0.x and a 255.255.255.0 mask. When I configure the router's gateway setting to the modem's static IP, it won't connect to the web. When I remove the public IP from the back office PC and assign it to the wifi router's IP setting, the router connects to the web but now the back office PC won't. I don't want that PC to point to the wifi router's IP as this will breach security, right?

It just seems like I'm missing a couple of steps here. It's a pretty simple SOHO network but I attached a quick diagram that might help visualize it a bit more. I hope I provided enough information but if not, let me know what else is needed. Thanks in advance.

Chris

After thinking about it, I realized that there wasn't a firewall appliance! Duh! Can anyone recommend a firewall that will allow me to have 2 networks secure from each other that will access the same DSL modem? Will any of them do that? I confess that I haven't set up a firewall before.

I would recommend a Watchguard for this...

http://www.watchguard.com/products/xtm-2/overview.asp

Sorry, I'd like to hijack for a moment. So a cash register can also be configured as an IP device ? Are these things easy to set up with IP addresses? Can they broadcast for an IP address or do they have to be configured manually ?

Furthermore, if a cash register can be configured with an IP address, that leads me to believe there is an operating system which allows this. Do cash registers use operating systems ?

Sorry, I should have used "point-of-sale" instead of "cash register". Usually POS systems use an OS like an embedded version of Windows or a Linux variant. There's just enough functionality to configure the POS to get on the network. They can also be a regular PC with POS software installed.

I see. I actually assumed you were talking about those machine where you can swip an ATM/credit card and type orders/fees into a touch screen or similar device. The kind you would see at a higher class bar or restaurant. thx