When you use the DHCP New Scope Wizard to define a range of IP addresses for a scope, select the Yes, I want to activate this scope now box, and close the wizard. the scope is NOT activated. When a client requests a DHCP address, they receive:
DHCP Server is unreachable.
To workaround this behavior:
1. Control Panel / Administrative Tools / DHCP.
2. Select the scope that you created.
3. Right-click the scope and press Properties. Insure that the settings on each tab are correct.
4. Expand the scope.
5. Right-click Scope Options and press Configure Options. Make sure that all the desired options are set.
6. Right-click the scope and press Deactivate.
7. Right-click the scope and press Activate.
NOTE: You must activate a scope to make it available. DO NOT active a scope until you specified all the required options.
NOTE: Once a scope is working, DO NOT deactivate it, unless you are permanently retiring the scope.