In case the DHCP server detects any inconsistencies, it allows the administrators to rectify the issue. While rectifying, the DHCP server uses the detailed information about the DHCP client computers, and assigns the inconsistent IP address settings to the corresponding client computers for a specific predefined lease duration.
With this approach, when the lease duration expires, all the inconsistent and inappropriately assigned IP addresses are revoked back to the DHCP IP address pool, hence making the entire DHCP database consistent.
It is important that the Enterprise Admin or Domain Admin (in case of client/server architecture), or local administrator account credentials (in case of standalone server) must be used while initializing the DHCP reconciliation process. If the above said accounts credentials are not used, you will not be able to perform the DHCP reconciliation whatsoever.
Here is how you can reconcile all the Scopes that a Windows Server 2012 DHCP server may have in order to check its consistency and integrity with the Windows registry:
- Log on to the Windows Server 2012 DHCP server with the appropriate account credentials.
- If not already started, initialize the Server Manager window from the bottom left corner of the screen.
- On the opened Server Manager window, from the left pane, click to select the DHCP category.
- From the right pane, under the SERVERS section, right-click the DHCP server from the displayed list.
- From the context menu that appears, click the DHCP Manager option.
- On the opened DHCP snap-in, from the left pane, expand the server name. (DC-01.MYDOMAIN.COM for this demonstration.).
- From the displayed list, click to select and then right-click IPv4 container.
- From the context menu that appears, click the Reconcile All Scopes option.
- On the opened Reconcile All Scopes box, click the Verify button to start the
- If the inconsistencies are present in the database, they will be displayed in the status window, otherwise you will be displayed with a message box informing you that the database is consistent.
- Click OK on the displayed message box.
- Once done, close the Reconcile All Scopes box, and then close the DHCP snap-in.