This tutorial explains the MAC (Media Access Control) address in detail. Learn what the MAC address is, how it is formed, and the types of MAC addresses (unicast, multicast, and broadcast).
Mac Address Manufacturer List Download 2018
Download MAC Address Scanner - Clear-cut application which enables you to quickly scan your entire network or a single host, so as to obtain their MAC addresses. MAC Address Block Large (MA-L) This product was previously referred to as an OUI (Organizationally Unique Identifier) and is still referred to as such in many standards. OUI is an IEEE Registration Authority (RA) specific term that is referred to in various standards and may be used to identify companies on the IEEE Public Listing.
In network, an address provides a unique identity to an end device. Unless an end device has a unique address, it can’t communicate with other devices in the network. A unique address enables an end device to send and receive data in the network.
In the LAN network, a unique address is the combination of two addresses; software address and hardware address.
Addressing in Networking Reference models
A networking reference model defines the standards, characteristics, definitions, and functionalities of the network. There are two popular networking models; the OSI Seven Layers model and the TCP/IP model.
![Mac Mac](/uploads/1/3/4/1/134186279/907641608.png)
In both models, the software address and hardware address are defined in the network layer and data link layer, respectively. In both models, the network layer and data link layer stand on the third and second positions, respectively. Because of this, both layers are also known as layer 3 and layer 2, respectively.
Software address
The software address is also known as the network layer address or layer 3 address. This address is manageable and configurable. Based on network requirements and layout, this address can be configured and assigned to an end device. Almost all modern LAN implementations use the IP protocol in the network layer. The IP protocol uses the term IP address to define the software address.
I have already explained IP addresses in the following tutorial.
In this tutorial, I will explain the hardware addresses in detail.
Hardware address
The hardware address is also known as the data link layer address or layer 2 address or MAC (Media Access Control) address. From these terms, the term MAC address is commonly used to refer to the hardware address. Unlike the IP address or software address, this address can’t be configured or managed. When you purchase a new NIC (Network Interface Card), or any device which has onboard NICs, it comes with a pre-configured MAC address.
A MAC address is 6 bytes (48 bits) long address in the binary numbers. MAC addresses are written in the hexadecimal format. The hexadecimal format uses the base-16 to refer to numbers. If we divide the total available length (48 bits) in binary numbers by the base (base-16) that is used to write a number in hexadecimal format, we get the total digits (12 = 48 ÷ 16) of that number in the hexadecimal format. Thus, if we write a 6 bytes (48bits) long binary MAC address in hexadecimal format, we get a 12 digits long hexadecimal number.
For convenience and easier readability, when writing a MAC address in hexadecimal format, extra space or periods or colons are added after every two or four digits. For example, you can write a MAC address in the following ways.
- Without any separator: - 00000ABB28FC
- Extra space after every two digits: - 00 00 0A BB 28 FC
- Extra space after every four digits: - 0000 0ABB 28FC
- Colon after every two digits: - 00:00:0A:BB:28:FC
- Colon after every four digits: - 0000:0ABB:28FC
- Period after every two digits: - 00.00.0A.BB.28.FC
- Period after every four digits: - 0000.0ABB.28FC
No matter which style you use to write the MAC address, or an application or networking software uses to display the MAC address, a MAC address is always processed in binary numbers only. NIC converts hexadecimal numbers of the MAC address in binary numbers before processing and using it.
Structure or format of the MAC address
As mentioned above, you can’t assign MAC address to a NIC or onboard NICs. When you purchase a new NIC or a device with onboard NICs, it arrives with a pre-configured MAC address or MAC addresses, respectively. Before we understand how manufacturers select MAC addresses for NICs, let’s briefly understand why a MAC should be unique in the LAN network.
If a LAN network has two or more NICs configured with the same MAC address then that network will not work. Let’s understand this with an example.
Suppose in a network three PCs; PC-A (11000ABB28FC), PC-B (00000ABB28FC) and PC-C (00000ABB28FC) are connected through a switch. NICs of PC-B and PC-C have the same MAC address 00000ABB28FC.
If PC-A sends a frame to the destination MAC address 00000ABB28FC, the switch fails to deliver this frame as it has two recipients of this frame.
The following image shows this example.
A LAN network does not work unless each device in the LAN network has a unique MAC address.
Now let's be back to our main question. How do manufacturers assign a unique MAC address to each NIC?
Before manufacturing NICs, every manufacturer obtains a universally unique 3-byte code, known as the organizationally unique identifier (OUI), from the IEEE. The IEEE is an international organization that regulates and maintains the namespace of MAC addresses.
After obtaining the OUI bytes, the manufacturer uses these OUI bytes at the beginning of the MAC address of all its NICs or on-board NIC devices. The manufacturer also assigns a unique hexadecimal value in the remaining bytes.
6 bytes MAC address = 3 bytes OUI number obtained from the IEEE + 3 bytes unique number assigned by the manufacturer
MAC addresses of all NICs or onboard NIC devices manufactured by the same manufacturer always start with the same 3-bytes OUI numbers. For example, suppose the IEEE assigns an OUI “0000AA” to the xyz company. Now the xyz company will use the OUI number 0000AA as the first 24 bits to build MAC addresses for its NICs or onboard NICs devices.
To keep each product separately from others, the manufacturer uses the remaining 3-bytes. Manufacturers are free to use any sequence or method on the remaining three bytes. For example, the xyz company can assign the MAC addresses to its NICs in the incremental order.
The following table extends this example and adds two more demo companies (ABC and JKL) in the example. It also shows MAC addresses of 5 NICs from each company.
![Download Download](/uploads/1/3/4/1/134186279/334663091.jpg)
Thus, this procedure ensures that no two NICs use the same MAC address in the universe.
Types of MAC address
There are three types of MAC address; unicast, multicast, and broadcast.
Unicast MAC address
Unicast MAC address represents a specific NIC or onboard NIC ports in the network. The inbuilt MAC address of a NIC is the unicast MAC address of that NIC.
Multicast MAC address
Multicast MAC address represents a group of devices (or NICs in Layer 2). The IEEE has reserved the OUI 01-00-5E (first 3-bytes or 24 bits) for the multicast MAC addresses. The remaining 24 bits are set by the network application or device that wants to send data in the group. A multicast MAC address always starts with the prefix 01-00-5E.
Broadcast MAC address
Broadcast MAC address represents all devices in the network. The IEEE has reserved the address FFFF.FFFF.FFFF as the broadcast MAC address. Any device that wants to send the data to all devices of the network, can use this address as the destination MAC address.
That’s all for this tutorial. If you like this tutorial, please don’t forget to share it with friends through your favorite social channel.
A freeware utility to spoof MAC address instantly
Mac Address Lookup By Manufacturer
Version 6.0.7
Windows 10/8.1/8/7/Vista/XP/Server 2012 R2/Server 2012/Server 2008 R2/Server 2008/Server 2003/Server 2000
Read this blog post to know what's new in this release.
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SHA2566E63BECAF5C5E17A9D3AFB6E2104EEE3DBE473C8930AE8783EBA0FEDADB4A152
Technitium MAC Address Changer allows you to change (spoof) Media Access Control (MAC) Address of your Network Interface Card (NIC) instantly. It has a very simple user interface and provides ample information regarding each NIC in the machine. Every NIC has a MAC address hard coded in its circuit by the manufacturer. This hard coded MAC address is used by windows drivers to access Ethernet Network (LAN). This tool can set a new MAC address to your NIC, bypassing the original hard coded MAC address. Technitium MAC Address Changer is a must tool in every security professionals tool box.
Features
- Works on Windows 10, 8 & 7 for both 32-bit and 64-bit.
- Enhanced network configuration presets with IPv6 support allow you to quickly switch between network configurations.
- Allows complete configuration of any network adapter.
- Command line options with entire software functionality available. You can select a preset from specified preset file to apply directly.
- Update network card vendors list feature allows you to download latest vendor data (OUI) from IEEE.org.
How Does It Work?
This software just writes a value into the windows registry. When the Network Adapter Device is enabled, windows searches for the registry value 'NetworkAddress' in the key HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlClass{4D36E972-E325-11CE-BFC1- 08002bE10318}[ID of NIC e.g. 0001]. If a value is present, windows will use it as MAC address, if not, windows will use the hard coded manufacturer provided MAC address. Some Network Adapter drivers have this facility built-in. It can be found in the Advance settings tab in the Network Adapter's Device properties in Windows Device Manager.
How To Change MAC Address
- Starting MAC address changer will list all available network adapters.
- Select the adapter you want to change the MAC address. You will get the details of your selection below.
- In the Information tab, find the Change MAC Address frame. Enter new MAC address in the field and click Change Now! button. You may even click Random MAC Address button to fill up a randomly selected MAC address from the vendor list available.
- To restore the original MAC address of the network adapter, select the adapter, click Restore Original button in the Change MAC Address frame.
NOTE: This tool cannot change MAC address of Microsoft Network Bridge. Network Bridge will automatically use the original MAC address of the first NIC added into bridge with the first octet of MAC address set to 0x02.
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