Networking

Tech Tip: Maintain the DHCP database

Microsoft recommends routine maintenance of the DHCP server component when its database exceeds 30 MB. While this is normally done automatically, you may have to manually repair the database if it gets too large between compactions.

Here's how to compact the DHCP database:

  1. Go to Start | Settings | Control Panel.
  2. Double-click Services.
  3. Highlight the DHCP Server service.
  4. From the Action drop-down menu, select All Tasks and then Stop.
  5. At the command prompt, change the default c:\winnt\system32\dhcp to c:\{system root}\system32\dhcp.
  6. Type jetpack dhcp.mdb compress.mdb.
  7. From the Action drop-down menu, select All Tasks and then select Start to restart the DHCP service.

This will compress the DHCP database into the Compress.mdb file, copy the Compress.mdb file back over Dhcp.mdb, and then delete Compress.mdb.

Backups of the DHCP server are also automated (generally every hour), but you can configure the system to back up more frequently. Follow these steps to change the DHCP backup interval:

  1. Start the Registry Editor (Regedit.exe).
  2. Browse to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\
    DHCPServer\Parameters\BackupInterval.
  3. Modify the contents of the BackupInterval key to the number of minutes desired between backups.
  4. Stop and restart the DHCP Server service.
  5. Close the Registry Editor and reboot.

Note: Editing the registry is risky, so be sure you have a verified backup before saving any changes.

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