Well, if I set my configuration to automatically obtain all these details, it will give me 255.255.240.0 as a subnet mask, but the problem is that my router (I'm behind a router) will only accept subnet masks such as 255.255.255.0, with a few variants on the 0. In the configuration page for my router (linksys BEFSR41), it has a drop-down list for available subnet masks, which very much limits what I can set the subnet mask to. My internet works fine and all that, between all three computer I have hooked up on the router, but I can't access my router's configuration's by going to
http://192.168.1.1/ unless I go in and manually specify that my default gateway is 192.168.1.1. When I do this, my internet stops working. I don't want to make this too long, so I'll see if any of this sounds familiar to anyone out there, so maybe they can help me. If you need more details, let me know and I'll post more details.