The first 2 paragraphs here at a direct copy paste from a previous post, but I shortened it to what we're actually having problems with now and took out the parts that weren't really important anymore. Hopefully since the Windows forum gets some more attention we'll be able to figure this out :D
So the network I run has a 10.0.0.1 subnet and a 10.0.1.1 subnet. Within the past few weeks I've noticed that more and more machines are appearing with Limited or No Connectivity. I went to my DHCP server and discovered there were a few machines coming up with BAD_ADDRESS which usually means something else is assigning them a DHCP lease or the machine is static and DHCP is trying to hand out that IP to someone.
Our current setup is that one of our servers has the DHCP server running on it, and a second DHCP server runs the other subnet and router. This server is a pain. It's really a pain. It was also our ISA server and I ditched ISA because there were way too many ways to get around it. I ended up purchasing a Barracuda Web Filter 310 and nobody can get by that so far. So I'm very happy with it. But the server still has to be there because it's running our router service.
Besides from this, our DNS service shows many different duplicate addresses. So it might show 10.0.0.1 and 5 or 6 different computers with a PTR record to that same IP. I'm having troubles pinging some new machines etc. What's worse is that many of the entries there, are old computer names that no longer exist in Active Directory. But scavenging doesn't delete them. A manual scavenge won't delete them. I'm wondering if I should just go ahead and manually delete every entry in DNS and DHCP and repopulate the fields after all the students and staff are out for the day and the machines are powered off and just let the machines power on the next day and fetch a new IP address. Before anyone asks, yes, the DHCP server is set to automatically update pointer records in DNS AND delete stale records [which it doesn't seem to be doing].
If anyone has any information on why this happened or how I can possibly make it cleaner, please do let me know.
I am not sure this will help but.
Is the dhcp service running on the computer ie does it have the green up arrow.
Have you run out of ip addresses in your range? This would cause clients to stop picking up ip.
Also have you enabled scavenging? This would remove not used ip from the dhcp so that they could be reassigned.
Are all the computers in the same area? You might have a connectivity problem like a switch going wonkie.
Lastly in the dhcp setting you can change the lease settings ie how long a computer holds an ip without trying to renew it.