Hi everyone, I'm administrator in my Windows 7 professional and I run cmd.exe with administrator rights. I also tried with UAC in its minimum. When I try to switch from the dynamic default gateway arp entry in the arp table to a static one with the following command: "arp -s 10.154.1.1 00-14-22-36-09-47" I have this message:"The ARP entry addition failed: Access is denied." This only happening with default gateway, if I try with other IP address it works fine. Regards

I got the same problem and i really dont understand why it fails only on the default gateway, considering that adding the default gateway arp entry in static is one of the solutions to a "man in the middle" attack If anyone got the anwer, i would be glad to see it

Please run the command as administrator and then run the arp commands. Additionally, if you try to add a new IP-to-MAC record for an existed IP address or MAC address, we are not able to realize it with arp commands in Windows 7. I suggest you use netsh command instead. Netsh commands for Interface Internet Protocol version 4 (IPv4) You may use the command add neighbors to add a IP-MAC setting, or use delete neighbors to delete it.Arthur Xie - MSFT