ISA Server does not provide control functions for the MAC address, Why? This is because the MAC address can only be used in the local network, when data packets across the router, the host in the packet source MAC address of the router the MAC address of the outbound interface instead, this time, use the MAC address The control does not apply. So long as the enterprise-level hardware or software firewall, have basically no control functions of the MAC address.

But Microsoft has also long been take into account this point, in Windows, if you install the TCP/IP network protocol component, then you can execute commands ARP. The ARP command is to look at the machine's ARP cache, static binding of IP address and MAC address and delete the static binding entry. In fact, the intention to bind the IP address and MAC address in order to reduce the ARP broadcast traffic, and only can use this function to control the use of IP addresses.

Or f describe the ARP protocol works under Windows. The ARP protocol is the Address the Resolve Protocol (ARP) in the second layer of the TCP/IP protocol - Data link layer for IP address translation for the network interface hardware address (MAC address, MAC address).

Whether any high-level protocol communications, and ultimately will be converted to the communication of the data link layer hardware address.

Each host has a ARP cache used to cache the MAC address list, you can use the command ARP-a or ARP-g to view the current ARP cache list. The ARP cache list is updated dynamically, by default, when one of the cache entries over two minutes of no activity, this cache entry will time-out is deleted. You can use the ARP-s IP address and MAC address to static binding, but in the Windows system before Windows Server 2003 and XP, even if you set a static MAC address binding, and also by receiving other packets destined for hosts update bound items.

Dynamic updates in Windows Server 2003 and XP, static binding will not, until the termination of the TCP/IP protocol, for example, restart your computer.

If you want to create a permanent static MAC address binding entry, you can write a script file to perform ARP static binding, the script can then use scheduled tasks to start your computer.

For example, host A IP address of, it now needs to communicate and IP is host (host B), then will conduct the following actions:

A host queries its own ARP cache list, if found to have a MAC address corresponding to the destination IP address, directly use the MAC address construct and send Ethernet packets, and did not find the corresponding MAC address are continue to the next step.

A host sends an ARP resolution request to the broadcast, the destination MAC address is FF: FF: FF: FF: FF: FF and requests an IP host to reply to the MAC address.
Host B receive the ARP resolution request to the broadcast back to the A host an ARP response packet, which contains its own IP address and MAC address.

A receives the ARP reply to host B, host B MAC address into its own ARP cache list, and then use the host B MAC address as the destination MAC address, host B IP address ( as the destination IP address to construct and send Ethernet data packet.
A host also sends data packet to, the IP address MAC address in the ARP cache list, A host directly using this MAC address to send packets, rather than sending an ARP resolution request broadcast ; when this cache address more than two minutes of no activity (not used), the ARP cache timeout is removed.

Default under the ARP cache timeout is two minutes, you can modify in the registry. Can modify key values have two, are located


Modify the key:

Key 1: the ArpCacheLife, type Dword, in seconds, default value is 120.

Key 2: ArpCacheMinReferencedLife type Dword, in seconds, default value is 600.

Note: these keys by default does not exist, if you want to modify, you must create your own.

Modified to restart the computer after the entry into force .

This address is