The address resolution protocol (ARP) cache is a table in computer memory that maps a limited number of IP addresses to their physical adapter addresses. A computer's ARP cache contains its own entry, entries for machines that have made ARP broadcasts to it, and entries for machines to which it has made broadcasts.
The Address Resolution Protocol (or ARP) is a very important part of IP networking. ARP is used to connect OSI Layer 3 (Network) to OSI Layer 2 (Data-Link).This means to communicate with any device on your network, you must have the Ethernet MAC address for that device. If the device is not on your LAN, you go through your default gateway (your router).
In this case, your router will be the destination MAC address that your PC will communicate with.To clear or flush ARP cache follow these steps:Step 1. Open Terminal.appStep 2. Insert this command to view whats in the cachesudo arp -aStep 3.a. Insert this command to delete only one interface in cachesudo arp -d 192.168.3.1 ifscope en0Step 3.b. Insert this command to delete whole cachesudo arp -a -dThat is it your ARP cache is cleared.
Click Start Control Panel.2. Click Administrative Tools.3. Click Computer Management.4. Double-click Services and Applications.5. Double-click Services.6. Scroll down to Routing and Remote Services.7. Double-click Routing and Remote Services.8.
Set the Startup Type to Disable.9. Make sure the service is stopped.Now try flushing the ARP cache again. It should work this time.It is also possible to troubleshoot network connections using the ARP cache. For example, it is important to look out for invalid ARP entries that go to a MAC address of 00-00-00-00-00-00. If one such entry shows up, make sure to delete it from the cacheusing the -d switch. Say you have an ARP entry that looks like: 224.0.0.24 00-00-00-00-00-00 staticIn order to delete this entry, use the arp command like so: arp -d 224.0.0.24And that invalid entry will be gone.Software Developer.