Abstract: It's  limited for the campus net, and it will be charged basing user' IP address, so it is possible that IP ddress are embez zled. It becomes an important security problem to prevent the IP address from embezzling. This article described a security way that binding IP address and MAC address combine with using access-list. This way not only can prevent IP address from embezzling, but also can control the user' access right.

Key words: IP address, MAC address, bind, ARP, ACCESS-LIST, security