Dynamic Host Configuration Protocol

Restoring Server Data

Restoring the DHCP server database can be useful if the database either becomes corrupted or lost. When this happens, Windows 2000 Server provides a progressive set of recovery and repair options for restoration of DHCP data on the server computer.

In troubleshooting data corruption problems, use the following steps to detect corruption and restore DHCP service.

First, confirm that the source of data loss or corruption is with the DHCP server and perform preliminary diagnosis or repairs, such as compaction of the DHCP server database. Also, it is a good idea to verify that corruption is not related to other problems or conditions with hardware or software changes. Where data loss occurs, verify the server computer disk drives are operating properly. In most cases, database corruption first appears in the form of Jet database error messages in the System event log.
Second, where repair fails, you can use simple recovery of the DHCP server from your available options for server backup. DHCP Manager provides a simple backup option to effectively back up the DHCP server database. You can also have other options for obtaining a backup copy of the database for use during restoration, such as from a recent tape backup of the server computer disk drives.
Third, when simple data recovery options are not available or are tried but unsuccessful, you can also try advanced data recovery methods provided with the DHCP console and Windows 2000 Server to recover specific information related to individual scopes stored in the DHCP server database.

If you determine that the DHCP services are running on both the client and server computers but the error conditions described earlier under "Troubleshooting DHCP Servers" persist, then the DHCP database is not available or has become corrupted. If a DHCP server fails for any reason, you can restore the database from a backup copy.

To restore a DHCP database

Before starting, make a copy of the DHCP server database files.
In the %SystemRoot%\System32\Dhcp directory, delete the J50.log, J50xxxxx.log, and Dhcp.tmp files.
Copy an uncorrupted backup version of the Dhcp.mdb (from your manual or automatic database backup media) to the %SystemRoot%\System32\Dhcp directory.
Restart the Microsoft DHCP server.