We have a Windows 2008 R2 Server with a DHCP server that manages a public IP net and a internal IP net. We use the latter for machine computers that are not supposed to show in the network and have restricted internet access.
All clients are supposed to get IPs from the public IP range. However, for a few weeks now, clients often get an IP from the private IP range (where they don't have network or internet access because they are not defined that way). The workaround that I tell my users is to try
ipconfig /release and
ipconfig /renew until they got the correct IP. I also tried
ipconfig /registerdns on the clients, but they keep getting the wrong IP.
As far as I know, nothing changed on the server. It is possible that this behaviour started with a round of Windows updates.
How do I get client PCs to alway grab the correct IP? Is it a DHCP or a client problem?
Disclaimer: I do administrate the server, but I basically inherited the duty and I am a complete newbie. I can manage users and register new clients, but that's about it.