I'm troubleshooting a certain issue with my DHCP configuration, and need my Windows machine to ask for a "fresh" IP address, so I can see which address DHCP server gives by default.
When I do ipconfig /release followed by ipconfig /renew, Windows "proposes" its old IP address to the DHCP server (just checked with Wireshark, initial "DHCP Discover" message has Option-50 (requested IP address) with Windows machine's old IP).
Tried disabling/enabling network adapter. Same behavior.
Question: How can I force Windows to just ask for a new IP address, without proposing its old IP address.
Best Answer
There is no procedure worth the effort. It's stored in a registry key, but that portion of the registry is cached while the network subsystem is running. So you'd have to shut the system down, boot another OS installation, mount the registry, delete the key, and then reboot into the original OS installation. The key is DhcpIPAddress but it is only used across reboots, so you can't modify it.
Uninstalling and re-installing the network adapter might work.