I am getting ready to demote a Domain Controller from our domain.
Yesterday I removed this server from the DNS listings of our DHCP clients. The only DNS servers assigned were the 2 other DC that were previously there and working fine.
Once their leases were renewed and they received these settings, the internet was hit or miss. Some sites didn't work at all while others took forever to load. It was clear to me at the time that it was looking for the other DNS server but it was not listed in their DNS servers and even if something was referencing it, it was still available.
I ended up putting it back into the scope and all has returned to normal. Here is my question:
Why did this happen? Does DHCP still know of it's existence even though I removed it?
If and when I demote this domain controller, will this automatically remove it from DHCP or will/or should I do this step again after?
Thank you for your help