Managing the DHCP Database Files

The following files are stored in the \systemroot\SYSTEM32\DHCP directory that is created when you set up a DHCP server:

• DHCP.MDB is the DHCP database file.
• DHCP.TMP is a temporary file that DHCP creates for temporary database information.
• JET.LOG and the JET*.LOG files contain logs of all transactions done with the database. These files are used by DHCP to recover data if necessary.
• SYSTEM.MDB is used by DHCP for holding information about the structure of its database.

Caution The DHCP.TMP, DHCP.MDB, JET.LOG, and SYSTEM.MDB files should not be removed or tampered with.

The DHCP database and related Registry entries are backed up automatically at a specific interval (15 minutes by default), based on the value of Registry parameters (as described later in this chapter).

After DHCP has been running for a while, the database might need to be compacted to improve performance. You should compact the DHCP database whenever it approaches 10 MB.

To compact the DHCP database

1. At the DHCP server, stop the Dynamic Host Configuration Protocol using the Control Panel Services option.

– Or –

At the command prompt, type the net stop dhcpserver command.

2. Run the JETPACK.EXE program (which is found in the \systemroot\SYSTEM32 directory) from File Manager or Program Manager.
3. Restart the Dynamic Host Configuration Protocol on the DHCP server.

Caution Do not compact the SYSTEM.MDB database.