Windows Home Server and Windows Small Business Server 2008 depend heavily on the router protecting your network to allow remote access to your server while away from the home or office. Both servers will attempt to use UPnP to automatically configure the router and keep it up to date, but on many routers, UPnP fails, or the router is reset etc. As a result, sometimes it’s the right thing to configure your router manually to ensure it just always works, regardless of if a UPnP call fails.
For this, I have recently been alerted to a great Wiki on HomeServerLand that goes through the UI for a bunch of common routers. Click here to find that Wiki database. While the database is designed for Windows Home Server, such that it creates DHCP reservations for the server on the network (Windows Home Server is configured with a Dynamic IP address on the Local Area Network (LAN) ). It also talks about how to configure a port, which is all you need for Windows SBS 2008.
Each router model listed has step-by-step instructions on how to configure both the DHCP exclusions and the port mappings.
To modify these steps for Windows SBS 2008, simply ignore the DHCP reservation steps, and instead get the IP address of your server by typing ipconfig at the command prompt on the server. The “IPv4 Address” is the address of the server you’ll want to give the router. Remember for SBS you need 80 and 443 (same as Home Server), and also 25 for email, and 1723 (if you plan on using VPN). Port 4125 is only used in Windows Home Server and SBS 2003 (the previous version of SBS).
And while you’re in your router configuration UI, make sure you turn the Wi-Fi security to WPA or WPA-2. Remember, WEP is easy to crack, and isn’t considered secure.
Again, it’s the Remote Access Router Configuration Wiki