I'm a casual developer frequently working on a variety of diverse platforms (Windows, Linux, embedded hardware, etc) with a network inquiry. I'm trying to take my desktop development system currently running Vista Ultimate, and add a 2nd IP to a NIC that already has a DHCP configuration for the local environment. There doesn't seem to be a way to do this, and want to see if I missed something. This 2nd address has no special routing requirements, and is used strictly in a link-local sense to connect to an embedded device to upload a build. I'm fully aware I can add multiple IP addresses on a single IP stack like this by setting them all to statically defined, but this has the detrimental effect of resetting ALL my open network sockets to make the change. Interactive applications abort or hang, and shell sessions must be individually re-established. This is of course sub-optimal, and I'd like to keep my existing DHCP settings and add a 2nd IP. I'm not always at the same physical location when I develop, so having to "just use static configuration" all the time is quite inconvenient. To demonstrate what I want to do, in Linux, the command "/sbin/ip address add 192.168.1.2/24 dev eth0" does precisely what I've described above, all without touching my automatically configured DHCP environment. I'd love to hear of a Windows Vista (or even Windows 7, if one exists!) way to do this. Thanks for any suggestions or comments!