I currently have a SOHOware NBG 800 broadguard wired router and I like the firewall features that it has that many other router/firewall combos do not have (SPI, for one.)
My girlfriend has an Intel Centrino notebook with a D-Link 614+ wireless router that she has been using. We are going to be consolidating all of this equipment into one network soon, and I am wondering if there is any way that I can place the D-Link router behind my SOHOware router firewall, while maintaining an intact LAN with file-sharing, etc. between the two computers?
I know that I could simply use her router alone, but I'd rather keep everything behind mine if possible and simply use hers as a WAP. What can I do?
The DI-614+ is a router/firewall - I don't think it can be configured to operate as a bridge. You can plug the 614 into an Ethernet port connected to your SOHOware, configuring the 614's WAN port with an IP address from your LAN and using your SOHOware's LAN address as the 614's "ISP Gateway Address." This will provide Internet connectivity, but creates two separate subnets. As a result of Network Address Translation, everything connected behind the 614 will appear to be coming from the 614's WAN port IP address. Your LAN will not be able to connect to destinations behind the 614 unless you configure the 614's "Virtual Server" feature to expose a particular destination IP/port (for example, an FTP server on your girlfriend's notebook).
NetBIOS broadcasts related to file sharing work only within a single LAN - they are not relayed by routers across subnets. As a result of this, and the 614's firewall/NAT features, you will not be able to browse fileshares on your girlfriend's notebook from PCs on your LAN. However, she can access fileshares and printers on your LAN, because she will be able to connect directly to them (for example, finding your computer by IP address, or configuring your computer's name into her etc/lmhosts file). If this doesn't meet your needs, consider buying an inexpensive wireless AP for her notebook to connect to instead. Unlike wireless router/firewalls, which are designed to deflect incoming traffic, wireless APs permit bi-directional LAN traffic, including NetBIOS broadcasts.