DHCP Fails to Assign DNS/WINS
The Issue
A few months ago a client came in from another part of the business and had an issue where the DHCP server appeared to not have given the PC any DNS entries. This of course was a big problem – DNS is critical to any PC wanting to talk outside of its own broadcast domain. I only had limited time to find a solution to the issue so I had to put together a work-around before coming to the root cause. The work-around was simple enough – Manually supply the DNS addresses and move on. But before the client left I managed to take a Wireshark packet capture of the DHCP event, and sure enough the DNS server addresses were definitely in both the DHCP offer and client response. So something was wrong with the clients’ PC.
All my research turned up was people with similar issues and no real pattern other than a certain sub-set of NIC chipsets. So when I saw it pop up again this week on a HP workstation I immediately got excited about the possibility of nailing this bastard of a problem. I recorded the NIC chipset details and went to work on isolating the issue. I first had to make sure this was really the weird DHCP problem described earlier – I made sure it wasn’t some DHCP scoping problem or an AD group policy of some sort, and finally I did a Wireshark capture. Sure enough, the DNS server addresses were definitely in there. So again, the PC knew about the DNS server address, but it just didn’t apply them. Why?
Luckily, after a lot of Googling I believe I’ve found the fix…