What Is MAC-Binding, and How Does It Work?

MAC-binding means binding the media access control (MAC) address to a device’s Internet Protocol (IP) address. Think about this as putting a nametag on every device that connects to a network. So, if there is a change to either the MAC address or the device’s IP address, you will not be able to connect to that network. With MAC-binding, the internet network can identify and communicate with the right device, making data transfer seamless and efficient.

MAC-Binding Explained

MAC-binding allows you to “bind” an IP address to a MAC address. After the binding, network administrators can restrict access to their network, only allowing connections from devices with specific MAC addresses.

What Is an IP Address?

The internet is a combination of different networks. Each network is known as an internet service provider (ISP). When you purchase service from an ISP, you will be given an IP address, and you’ll be able to access other networks connected to your ISP.

An internet protocol (IP) address is a distinct numerical label assigned to every device that explains its location on a network. When data from the internet needs to reach you, your ISP’s network uses your IP address to route the data to you.

There are two models of IP addresses: static and dynamic. A dynamic IP address changes when the connected device disconnects from the network. This IP address can even be assigned to another device when it is not in use. A dynamic IP is assigned automatically by a DHCP (Dynamic Host Configuration Protocol) server.

However, a static IP address is assigned to a device by the network administrator and does not change.

What Is a MAC Address?

A MAC address (also called a media access control address) is a 12–character unique identifier. Unlike IP addresses that can change when a device connects and disconnects from the network, MAC addresses are assigned by the device’s manufacturer and remain the same for a device.

How Does MAC-Binding Work?

For MAC-binding to work successfully, the network administrator has to create a list of authorized MAC addresses and their associated IP address on the DHCP server. This list is called the MAC-binding table.

So when your device requests an IP address to the DHCP server, the network administrator looks through the list to confirm if your device’s MAC address is authorized and on the binding table. Once confirmed, you’re assigned a corresponding IP address from the table.

The DHCP server also assigns a lease time with the IP address. If your device is still connected around the time the lease expires, it’ll request another IP address. After disconnection, your device requests to release the IP address, which the server can assign to another device.

This way, MAC-binding ensures the same IP address is assigned to a MAC address, helping to maintain a stable network configuration. Network administrators can also use MAC-binding to detect the device that carried out a specific online activity.

5 Advantages of MAC-Binding

MAC-binding prevents unauthorized access to your network, as only those with approved MAC addresses would be allowed entry. If you change your IP or MAC address, you will be unable to access the network. Measures such as these make your network more stable and secure. Also, network administrators can use MAC-binding to trace online activities to a specific device.

1. Improved Security

With MAC-binding, there can be no third-party access. Only registered MAC addresses would be assigned IPs and be able to communicate on the network. This layer of security is useful against threat actors, as it blocks unauthorized entry.

2. More Control

MAC-binding gives network administrators more control over their network: it enables them to choose who communicates on the network, block or restrict access to only certain devices, and limit access to sensitive data.

3. Device Identification

Threat actors are becoming harder to apprehend due to their detection evasion techniques. But with MAC-binding, any suspicious activity is flagged and can be easily traced to the origin device, as each MAC address is registered on the network’s servers.

4. Improved Efficiency

Different devices may have the same IP address. But with MAC-binding, the DHCP (Dynamic Host Configuration Protocol) server can make sure no two devices have the same IP address. This is because each device is singly registered on the network. And by eliminating any chance of IP conflicts, network efficiency and connectivity are improved.

5. Reserved IPs

Mac-binding also allows network administrators to reserve IP addresses for “special” devices. This way, firewall policies can be configured and priority given to certain devices.

MAC-Binding: Limitations and Loopholes

Though MAC-binding has many advantages, it has a few limitations and disadvantages that you should consider.

1. MAC Address Spoofing

Indeed, each MAC address comes directly with your device, assigned by its manufacturer. But MAC addresses can be altered or completely changed. Threat actors use MAC address spoofing to hack wireless networks and steal sensitive information and login credentials.

2. The Volatility of IP Addresses

Once you disconnect and reconnect to a network, the IP address of your device changes, and it is possible for threat actors to “hide” behind a particular device. This is called IP masking.

A second device can connect to a registered one and perform all online activities through it. However, to the network, the registered device would be the only one present. There would be no trace of the second device.

No new IP address is created, as the second device is simply “masking” its IP with that of the registered device.

3. Limited Flexibility

Your device will only be able to access the network if it is registered on the DHCP table. And even though this is an extra layer of security, it can be bypassed by spoofing your MAC address to resemble that of a registered device.

4. Stressful Manual Configuration

MAC-binding can be stressful and time-consuming. For example, as a network administrator, you must manually register new devices in the DHCP table. Also, you must regularly update the table as new devices are added to the network and existing devices are removed.

MAC-Binding: An Extra Layer of Security

Although MAC-binding adds an extra layer of security to your network, it should not be considered a complete replacement for other security measures. You can use it with other measures such as firewalls, encryption, and access controls.

MAC-binding has many advantages, and its merits completely outweigh its limitations.

If you’re still not sure about Mac binding, welcome to contact our technical staff  at Hubtech limited for a professional technical consult.