How to Clear ARP Cache in Windows 10

Whenever you are troubleshooting networking issues, a wide range of potential problems needs to investigate. One potential issue is that the ARP cache contains incorrect data actually. This scenario is extremely unlikely and is most often caused by a user that is editing their own ARP cache for some purpose. However, no matter how the issue was caused, it still needs to be fixed actually. So, do you know what is the ARP cache, and how do you clear it? We are going to discuss How to Clear ARP Cache in Windows 10.

What is the ARP cache?

ARP basically stands for Address Resolution Protocol, it also resolves IP addresses to MAC addresses. And is basically use exclusively for communications over a local network. The ARP cache saves routing information for local IP addresses, and then it actually contains a default route to the gateway, for external resources actually.

You can only modify the ARP cache through a device on the local network. ARP messages are broadcast to the whole local network. Any device that can see ARP messages will actually adjust its ARP cache in order to match the newest information. Thus, changes to the cache on a device can be made by a user, or potentially a virus on any device on the network. We cannot directly modify the ARP cache via users outside of the local network actually.

Tip: Modifying the ARP cache manually should not be done lightly actually, because it can cause networking issues.

The most likely cause for the ARP cache needing to clear is the user of the device. That is trying to modify their own cache via hardcoding a value in an attempt in order to fix an issue and making it, even more, worse via accident.

How to Clear ARP Cache in Windows 10

Well, the first step to clearing the ARP cache is to open an elevated command prompt, doing this basically gives it administrative rights that are important to perform the deletion. Open the windows start bar and then you have to type “CMD”. Then just right-tap on the command prompt and now select “Run as administrator”.

clear arp cache

In the elevated command prompt you have to type the command “arp -a” to view the ARP cache. In order to clear all the ARP cache run the command “arp -d”. The -a flag instructs the program to display the ARP cache, the -d flag instructs it to delete the cache as well.

clear arp cache

Other ARP commands:

arp -a Display a list of ARP entries
arp -d <ip #> Delete an IP address from the ARP table
arp -s <ip #> <mac #> Add a static IP to a MAC address in the ARP table
Example:  arp -s 231.32.54.315 00-FF-23-44-d7-11

Verify the flush

Whenever you guys have to flush the ARP cache, make sure to issue the command arp -an in order to see if the cache has, in fact, flush. If it does not flush, then it could be the system is a victim of a Windows bug caused whenever Routing and Remote Services is turned on. This is actually a really simple bug to fix:

  • Tap on Start | Control Panel.
  • Then click Administrative Tools.
  • Press the Computer Management.
  • Double-tap Services and Applications.
  • Double-click on the Services.
  • Now scroll down to Routing and Remote Services.
  • Double-tap on Routing and Remote Services.
  • Then set the Startup Type to Disable.
  • Also, make sure the service stop or not.

Now try to flush the ARP cache again. It should work this time actually.

Troubleshooting

Well, it is also possible to troubleshoot network connections via the ARP cache. Such as, it is necessary to look out for invalid ARP entries that actually go to a MAC address of 00-00-00-00-00-00. If one such entry shows up, then you have to make sure to delete it from the cache via the -d switch. Say you have an ARP entry that actually looks like:

<em>224.0.0.24           00-00-00-00-00-00 static</em>

In order to remove this entry, use the arp command like this:

<em>arp -d 224.0.0.24</em>

And that invalid entry will be gone now.

Conclusion

Alright, folks, I hope you like this article and understand now. If you have any issues and queries related to it, just comment down and let us know.

Keep Smiling!

Also See: How to Reset DNS Cache in Windows 10

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