Easily modify the MAC address of the NIC in Windows

Now we all use ADSL to access the Internet. When you query the internet, you will find that every time you access the Internet, China Telecom records the MAC address of your Nic. This is because the IP address is dynamic (each time you access the Internet ), the MAC address remains the same-each Nic has a unique MAC (physical) address, so the MAC address becomes the customer's online id card. by recording the MAC address, you can confirm it is your network!

　　I. Usage of MAC addresses

The MAC address is fixed in the NIC, And the MAC address of each Nic is different. During the preparation of the NIC, the manufacturer will burn a set of numbers in its EPROM, which are different from each other. This is the MAC (physical) Address of the NIC.

The MAC address is unique, so it is mainly used to identify users in the network. For example, when using ADSL to access the Internet, China Telecom uses it to charge fees and confirms that it is your network. In the campus network, MAC addresses can also be used to identify users. For official users on the campus network, the MAC address will be registered on the server. If you are an illegal user, the server will not have the MAC address of your Nic. In this way, when you try to connect to the Internet, the server immediately recognizes you and stops you from connecting to the network.

　　2. the MAC address can be modified.

In some scenarios, for example, impersonating a formal user in the network, you need to modify your Nic Mac. To modify the MAC address, you can use the hardware method, that is, using the program modified by the NIC manufacturer to burn the eeprom of the NIC, however, the operation is highly risky and complicated. Even if you have experience, errors may occur during the operation.

In fact, you do not need to use the burning method to modify the MAC address in the NIC. You must know that when Windows is installed, it will automatically read the MAC address from the NIC and store it in the Registry for future use. When data is transmitted over the network, a source MAC address is required in the packets sent from the NIC. This MAC address is read from the Registry (not from the NIC ), therefore, if you modify the MAC address in the registry, it is equivalent to modifying the MAC address in the nic eeprom. The actual effect is the same!

　　3. Modify Mac in the Registry

1. Use software modification

This method applies to all types of NICs. In different windows, use different software to modify the Mac.

(1) win2003/XP/2000

If your system is win2003/XP/2000, you can use SMAC (http://www.klcconsulting.net/smac/#Download ). This software cannot modify the MAC address in the NIC, but can only modify the MAC address in the registry.

The software has two running modes. If you enable the "Windows Management Instrumentation (Wmi)" service, the software runs in [WBEM on] mode, more Nic information is displayed. Otherwise, the system runs in [WBEM Off] mode and the current running mode is displayed in the title bar of the software window.

The use of the software is very simple. After running, click "refresh". The list box in the window will display the NIC type, IP address, active Mac, etc, in the following six input boxes, enter your specified MAC address (Figure 1), and then click "Update Mac" on the right to complete the modification. Then, restart your computer to make the modification take effect.

Figure 1

Note: you cannot enter a new MAC address for the trial version. You can only change the MAC address to 0c-0c-0c-0c-0c-01.

(2) Win98

If your system is Win98, we recommend that you use the "Mac scanner". This tool can modify the MAC address in the Registry, and then restart your computer to make the modification take effect.

2. Modify Nic attributes

 

If your Nic uses the RealTek rtl8139 chip, you can modify the MAC address in the NIC attribute so that the MAC address in the registry will change as follows:

In win2003/XP/2000, click "start"/settings/control panel, double-click "system", and click "hardware"/Device Manager, expand "network adapter" in the Device Manager, right-click the NIC whose MAC address you want to modify, and select "properties". Click the "advanced" tab. Under "properties, click the network address project (Figure 2) and enter the MAC address value (for example, 020202020202) under the "value" on the right ), note that 12 digits or letters must be entered consecutively (do not enter-in the middle). After restarting the computer, the modification will take effect. The Mac modification method under Win98 is similar to the above method.

Figure 2

If you want to restore the MAC address in the Registry to its original state under win2003/XP/2000 after modification, you can select the "Network Address" item, select "not exist" as the value on the right and restart the instance. In Win98, select "not displayed ".

3. modify it in the Registry

For non-rtl8139 NICs, you can directly modify the Mac in the registry. Note: Before you modify the registry, back up the registry.

(1) win2003/XP/2000

Click Start/run, enter Regedit to open the registry, and locate HKEY_LOCAL_MACHINE/system/CurrentControlSet/control/class/{4d36e972-e325-11ce-bfc1-08002be10318}/0000, 0001, 0002, and other primary keys, find the driverdesc content and find out which primary key is used by the NIC (for example, 0001). If the primary key has a Params entry, the primary key is also used by the NIC;

For example, if the network adapter uses the 0001 primary key, We will select it, create a string (named networkaddress) on the Right, double-click the string, enter the MAC address value you specified (note that it must be a 12-digit consecutive number or letter without a-sign ); add a sub-Key (networkaddress) to NDI/Params under 0001, select this sub-key, and add a string named default to the right of the sub-key. The key value is the modified MAC address, the value is the same as the value above. The modification takes effect after restart.

(2) Win98

Click Start/run, type winipcfg, select the NIC you want to modify, and record the MAC address value. Then click Start/run, and enter Regedit to open the registry, go to HKEY_LOCAL_MACHINE/system/current ControlSet/services/class/net. subkeys such as 0000, 0001, and 0002 are listed below; click the "0000" subkey and search for the "driverdesc" key under the subkey until the recorded MAC address is found;

For example, if the network adapter uses the 0001 primary key, We will select it and create a new string named networkaddress on the right side of it, and then double-click the string, enter a new MAC address value (note that it must be a 12-digit continuous number or letter without a hyphen). restart the computer to make the modification take effect.

4. Linux

 

If your system is Linux and you want to modify the MAC address in the system (for example, change to 020202020202), use # ifconfig eth0 down to disable the NIC first; otherwise, the system will be reported busy, cannot be changed; then use ifconfig eth0 HW ether 020202020202.

If you want to permanently modify the MAC address in the system, you can do this: in/etc/rc. d/RC. add the following three lines to local (you can also add them to/etc/init. d/network to add the following three lines)

Ifconfig eth0 down

Ifconfig eth0 HW ether 020202020202

Ifconfig eth0 up

　　4. Have you changed the MAC address?

If you want to know whether the MAC address in the system has been modified successfully, restart the computer and enter the ipconfig/all command at the command prompt, then, the right side of physical address will display an address. You can check whether the MAC address has been modified successfully.