I've run into a situation that has defied all my online research so I'm hoping someone can point me in the right direction. I have two DHCP servers (separated geographically) with "non-standard" server option definitions that I am attempting to remove. I say "non-standard" because out of the 8 DHCP servers deployed, these two are the only ones with these option definitions. They are:
132 Enable NBT hostname resolution
133 Enable gethostbyname() WINS resolution 134 Hostname resolution order
136 Enable WINS proxy agent
No matter what action I take - using the DHCP MMC console, using PowerShell, or using netsh - these settings under Predefined Options and Values persist. For each action, I receive the following:
Delete via DHCP MMC console - in the console, I select "Set Predefined Options..." and in the new dialog, I scroll down to one of the options I wish to delete. I click "Delete" after selecting the option, which is then removed from the list. After clicking "OK" however, I'm told "The specified option does not exist. (Option #)". When I close and re-open the DHCP console, the option is back in the list.
Using PowerShell - I execute the following command on the DHCP server:
Remove-DhcpServerv4OptionDefinition -OptionID 136
Which returns the following error:
Remove-DhcpServerv4OptionDefinition : Failed to delete option definition 136 on DHCP server [REDACTED]. At line:1 char:1 + Remove-DhcpServerv4OptionDefinition -OptionID 136 + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : ObjectNotFound: (136:root/Microsoft/...ptionDefinition) [Remove-DhcpServerv4OptionDefini tion], CimException + FullyQualifiedErrorId : DHCP 20010,Remove-DhcpServerv4OptionDefinition
Using netsh - I execute the following command on the DHCP server:
netsh dhcp server delete optionvalue 136
The specified option does not exist.
And yet in all cases, the options persist in both the console and querying the list of options via PowerShell. If I query for the specific value, however, it returns the fact that the option is not found.
I have tried restarting the DHCP service on both servers, with no change.
One server is Windows 2012 R2, while the other is Windows 2008 R2.
Neither of these servers is configured for failover. (Feature doesn't exist in 2008.)
None of these server option definitions are used in any of the scope configurations on these servers.
This is an environment that I've inherited through a job/company change, so I don't have much information on the history of these servers. Any thoughts, blogs, articles, or ideas would be appreciated. Thank you in advance for your time.