How to Clear the ARP Cache in Windows 11

The Address Resolution Protocol (ARP) cache is a vital networking component in Windows 11. It temporarily stores the mapping between IP addresses (like 192.168.1.10) and physical MAC addresses on your local network. This cache prevents your computer from constantly broadcasting requests across the network every time it needs to send a packet.

However, if a device on your network changes its IP address, or if a router is replaced, your Windows ARP cache might hold outdated or corrupted information. This can result in unexplained network timeouts, “destination host unreachable” errors, or an inability to connect to local printers and servers.

Clearing (or “flushing”) the ARP cache forces Windows to rebuild these mappings from scratch.

How to View Your Current ARP Cache

Before deleting the cache, you may want to view its current contents.

1. Press the Windows key and type cmd.
2. Click on Command Prompt. (You do not need administrator privileges just to view the cache).
3. Type the following command and press Enter:

   arp -a

4. Windows will output a list of interfaces and the corresponding IP-to-MAC address translations currently stored in memory.

How to Clear the ARP Cache Using Command Prompt

To modify or delete the cache, you must use an elevated command prompt.

1. Press the Windows key and type cmd.
2. Right-click on Command Prompt and select Run as administrator. Click Yes on the User Account Control prompt.
3. Type the following command exactly as written:

   arp -d *

4. Press Enter.

Unlike many Windows commands, arp -d * does not output a “Success” message. It simply drops you back to the command prompt line. The asterisk (*) is a wildcard that instructs Windows to delete every entry across all network interfaces.

How to Clear the ARP Cache Using PowerShell

If you prefer using modern Windows administration tools, you can achieve the exact same result using PowerShell.

1. Right-click the Start Menu icon (or press Windows key + X).
2. Select Terminal (Admin) or Windows PowerShell (Admin).
3. Type the following cmdlet and press Enter:

   Clear-NetNeighbor

PowerShell is slightly more interactive than the old Command Prompt. It will prompt you to confirm the action. Type Y for Yes and press Enter.

Once the cache is cleared, you do not need to restart your computer. Windows will immediately begin broadcasting ARP requests to rebuild the table with fresh, accurate data the moment you try to access the network.