I asked this question before, but seems to have been forgotten. Will Linux lock my static IP address so that when I reboot into Windows my internet connection will not work? If so, how will I be able to release my IP address (on a LAN) from linux?

The moment you shutdown/reboot your computer the ip assignment to the network card is lost, no matter what OS.

The only reason I can think of that you might have an IP address problem booting between two OSes is if you are using DHCP for automatic assignment of IP address. The DHCP server does usually allow the booting OS to specify a preference as to IP address (e.g. the last IP address it was assigned).

I am having a similar problem with my @home connection... the IP I get is from a dhcp server that seems to never expire. How do I release it so i can swith to another machine? ie: I need to do the equivalent of RELEASE using winipcfg in windoze. Rebooting or assigning new IPs to the NIC does nothing, and i think the ip is tied to the MAC address from the dhcp server's point of view.

The DHCP server doesn't tie the MAC address to the IP permanantly. The way it works is that the DHCP client remembers the last IP address it had and sends it to the DHCP server as a prefered IP. If it's available, the server will give it to the client. Or at least, that's the way it's *supposed* to work.

You can actually, from the dhcp server side, make a static assignment of an IP and in that case the MAC address would be the reference for dhcp server to know what IP to assign. This is probably not the case here.

Let's take a look on how the dhcp thing works.
When booting the client sends out a dhcp request on the broadcast address. Every dhcp server within that broadcast domain, in other words computers on the same side of a router, sends a response to the client with a dhcp offer.
If more than one server respond the client can choose from the offered leases and then it sends an acknowledge response to the server from which it decide to use the IP. The other servers not getting a response assume their IP wasn't selected.

Most of the time when having problem with dhcp the problem are on the client. Clients can be pretty stubborn. Forgot to tell that the client can request for a preferred IP when asking the servers and if that IP are available the servers might offer it.
Also the previously leased IP tend to be tried the next time and if it still is free then the server suggest it.
The lease time can also be set to not expire, called a permanent assignment.