Hi, I've been looking for a way to set the default subnet mask XP uses. For example, if I set my network card to "obtain an IP address automatically", Windows chooses the subnect mask of 255.255.0.0 but I want 255.255.255.0. Is there a way to set XP so it will use the subnet mask I want without specifying it in my TCP/IP options? Configuring the internal DHCP server I suppose.

On top of that, my network card used to choose an IP in the 192.168.0.* range when I would get it to obtain one automatically. However, I attended a private LAN a while back which had a dodgy hub in play, and since then my network card wants to default to a 169.*.*.* IP. Is there a way to restore this problem?

I know I can set the IP and subnet mask manually, but doing that prevents Windows from obtaining a gateway and DNS servers automatically, which is what I really need becuase they change often as I move my computer around.

Thanks for any help.

The subnet mask is set by DHCP. You can't manually change it if you're getting your TCP/IP info from a DHCP server. If you did, you wouldn't be connected to the network anymore as changing the subnet mask would also change the network you're on.

Where DHCP is concerned, your NIC doesn't 'choose' anything. All TCP/IP information comes from the DHCP server. Whatever IP address you're showing now is due to whatever DHCP server you're getting your info from.

if you choose to obtain an IP automatically then the 169... address is automatically assigned by windows if it cant find a DHCP server.