Friday, September 28, 2007

Address Resolution Protocol Cache

Viewing the ARP Cache

If you would like to view your ARP cache, this can be accomplished using the `arp` command:

C:\>arp -a

Interface: 192.168.1.100 --- 0x10004

Internet Address Physical Address Type
192.168.1.1 00-0f-66-37-22-32 dynamic

If Clearing the ARP Cache Fails

Occasionally, clearing your ARP cache will fail due to a bug in Microsoft Windows.

If you try to use Microsoft Windows to repair the network connection, you will receive an error message that says:

“Windows could not finish repairing the problem because the following operation could not be completed:
Clearing the ARP cache for assistance, contact the person who manages your network”

This bug occurs when Routing and Remote Services is enabled. Routing and Remote Services is almost unnecessary and can be turned off unless you know that you are using it.

To disable Routing and Remote Services:
  • Click the “Start” button
  • Click the “Control Panel” button
  • Switch to "Classic View" if you are in "Category View"
  • Click “Administrative Tools
  • Click “Computer Management
  • Double-click “Services and Applications
  • Double-click “Services
  • Scroll down to “Routing and Remote Services
  • Double-click “Routing and Remote Services"
  • Examine the "Startup Type"
  • The options are "Automatic", "Manual", and "Disabled"
  • Set the "Startup Type" to "Disabled"
  • Examine the "Service status"
  • Make sure that the service status is stopped. If it is not Stopped, click the “Stop” button
  • Click the “OK" button
Now, try clearing the ARP cache again and it should complete with no error messages.