How to prevent IP addresses from being stolen

On Campus Networks, the most convenient way to disrupt is to steal others' IP addresses. Computers with stolen IP addresses are not only unable to use the campus network normally, but also frequently prompt the dialog box when IP addresses are occupied, it brings great risks to campus network security and user applications. Binding IP addresses and MAC addresses can effectively avoid this phenomenon.

What is MAC address?

Two types of IP addresses are available for NICs. One is the IP address that everyone is familiar with, and the other is the MAC address, that is, the physical address of the NIC, also known as the hardware address or link address, this is the only identifier of the network card. It is like our ID card and cannot be changed at will. It has nothing to do with the network. No matter where the network adapter is connected, the MAC address remains unchanged. The length is 48-bit binary, from 12 00 ~ 0FFH consists of hexadecimal numbers. Each hexadecimal number is separated by "-", for example, "00-10-5C-AD-72-E3 ".

How to find a MAC address

1. Under Windows 9x/2000/XP, click Start/program and locate MS-DOS mode or command prompt ".

2. Enter "Ipconfig/all" at the command prompt, and press enter to display the dialog box shown in the figure. The "Physical Address" is the MAC Address.

How to bind MAC addresses and IP addresses

Go to MS-DOS mode or command prompt and enter the command: ARP-s 10.88.56.72 00-10-5C-AD-72-E3 at the command prompt to bind the MAC address and IP address together.

In this way, no IP address is stolen and the campus network cannot be used normally (of course, no error prompt dialog box is displayed), which can effectively ensure the security of the campus network and users' applications.

Note: ARP commands are only useful for LAN proxy servers and for static IP addresses. If Modem is used for dial-up or dynamic IP addresses, they do not work. The parameters of the ARP command have the following functions:

ARP-s-d-

-S: bind the corresponding IP address to the physical address, as shown in the example in this article.

-D: Delete the binding between the corresponding IP address and the physical address.

-A: query the ARP Protocol table to display the IP address and the corresponding physical address.