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
Which returns:
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.
Other notes:
- 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.
-Todd
