Rerouting network traffic from a SBS

Question

My friend's small office uses a network setup of a 48-port switch (Netgear GS748T), a VPN firewall (Netgear fvs336g), a Comcast modem and a Windows Server 2003 machine. We want to take down the SBS2003 server from the network, because it's an old machine using a lot of electricity and nowadays it's only used for sharing the internet access.

This friend was told by a local IT guy who was in the office for a while that the only thing that needs to be done in order to remove the server is to just physically turn it off and disconnect it and the internet access traffic should be re-routed. I unjoined a test PC connected to the network/server from the local domain (just to be sure) and then turned the server off. However, it's not so simple - after doing this, the internet access is down on all connected workstations. It's still routing to the server.

I'd really appreciate some general tips on why would that happen. I only had a few minutes today to take a look at the network and to check what's going on. As far as I remember, the internet access (modem/DSL) connects to the firewall, and then the firwall connects to NIC1 card of the server, then it goes out from NIC2 card to the switch and then it goes to the clients from the switch. Is that setup even possible? If so, then if I wired the firewall straight to the switch, will we be able to not use the server anymore?

I think this is our current setup:

DSL Modem -> Firewall -> first network card of server -> goes out to the second network card -> switch -> clients

Answer 1

The setup you describe is possible and does not even surprise me for a SBS setup.

I can only guess but I would say the SBS server act as DHCP server and Router.

You can remove it and connect the firewall to the switch but you probably will have to reconfigure the firewall.

You have to consider

• IP address space used
• need for a DHCP server or not
• NAT to be performed by the firewall
• Firewall rules to allow traffic from the client PCs to the Internet.

This is likely that there's a IP network between the firewall and the SBS server different than the one use between the client computers and the SBS server.

Also you must check that there's no Group Policy applied that would enforce some network settings on the client computers, such a proxy settings and Windows Software Update settings.

If there's those kind of GPO you must remove them in a way that they will no more be applied on the computers (there's a Check box in the GPO settings that tell if the settings are still applied when the GPO is removed).