What Is a MAC Address? How to Find and Look Up Yours

Every network device you own has at least one MAC address. Your laptop, phone, smart TV, console, and printer all carry one. It is burned into the hardware at the factory. When your laptop sends a packet, the router identifies the sender by its MAC address. It does not use the IP address for that.

Most people never notice their MAC address. You meet it when you set up MAC filtering or reserve a DHCP address. You also meet it when registering a device on a campus network. This guide explains what a MAC address is. It covers how the address differs from an IP address, how to find yours, and the privacy questions it raises.

What Is a MAC Address?

A MAC address is a 48-bit hardware identifier assigned to a network interface at manufacture. It works at Layer 2 of the OSI model, the data link layer. Devices use it to identify each other on the same local network, before any IP routing happens.

A MAC address (Media Access Control address) is a unique identifier for a network interface controller (NIC). It works at Layer 2 of the OSI model, the data link layer. That means it handles communication between devices on the same local network. This happens before IP routing enters the picture.

Every MAC address is 48 bits long (6 bytes). It is written as six groups of two hexadecimal digits. You will see it formatted in several ways, depending on the operating system and vendor:

• Colon-separated: A4:83:E7:2F:5B:10 (Linux, macOS)
• Hyphen-separated: A4-83-E7-2F-5B-10 (Windows)
• Dot-separated: A483.E72F.5B10 (Cisco equipment)

All three notations represent the exact same MAC address. The difference is purely cosmetic.

The MAC address is typically burned into the NIC firmware during manufacturing. That is why it is sometimes called a hardware address, physical address, or burned-in address (BIA). Every Ethernet port, Wi-Fi adapter, and Bluetooth radio has its own MAC address. A laptop with both Ethernet and Wi-Fi has at least two.

The 48-bit space yields roughly 281 trillion combinations (2^48 = 281,474,976,710,656). That is large enough for the IEEE to keep assigning unique blocks for the foreseeable future.

MAC Address vs IP Address

A MAC address is a permanent Layer 2 hardware identifier used within one local network segment. An IP address is a logical Layer 3 identifier, assigned by the network and routable across the internet. ARP links the two by resolving a target IP to its MAC address.

People often confuse MAC addresses and IP addresses. Both are “addresses” tied to network devices. But they serve different purposes and operate at different layers of the stack.

Here is the key relationship between them. When your computer sends data to another device on the same subnet, it uses ARP (Address Resolution Protocol). ARP translates the destination IP address into a MAC address. The Ethernet frame that travels over the wire carries the MAC address. The IP address rides inside the payload. Without the MAC address, the frame would not reach the right device.

What Is an OUI?

The OUI, or Organizationally Unique Identifier, is the first three octets of a MAC address. The IEEE assigns these prefixes to each manufacturer. Because the assignments are public, a lookup tool can read the OUI and name the vendor.

The first three octets (24 bits) of a MAC address are the OUI — Organizationally Unique Identifier. This portion identifies the manufacturer that produced the interface. The manufacturer assigns the remaining three octets to individual devices. That keeps each address unique within the allocated block.

For example, in the MAC address A4:83:E7:2F:5B:10:

• A4:83:E7 — the OUI, identifying the manufacturer (here, Apple)
• 2F:5B:10 — the device-specific portion assigned during production

The IEEE manages OUI registration through its Registration Authority. Manufacturers buy OUI blocks, and the assignments are published in a public registry. This is what makes MAC address lookup tools possible. They cross-reference the OUI against the IEEE database to name the vendor.

An OUI lookup is genuinely useful in network administration. Suppose you see an unknown device at DC:A6:32:xx:xx:xx. A lookup reveals it is a Raspberry Pi. If you spot 00:50:56:xx:xx:xx, that is a VMware virtual machine. This helps you identify devices and detect unauthorized hardware quickly.

The IEEE also offers smaller blocks for vendors that need fewer addresses. MA-M blocks use 28-bit prefixes, and MA-S blocks use 36-bit prefixes. These suit makers that do not need a full 16 million device addresses.

How to Find Your MAC Address

You can find your MAC address in two ways on any device. Use the system network settings, or run a command-line tool. Common commands are ipconfig /all on Windows, and ifconfig or ip link on Linux and macOS. Your router admin page also lists the MAC address of every connected device.

The steps differ by operating system. Here are instructions for every major platform.

Windows (Windows 10 and 11)

Command line method. Open Command Prompt or PowerShell and run:

ipconfig /all

Look for the line labeled “Physical Address” under your active adapter. The value looks like A4-83-E7-2F-5B-10. With multiple adapters, each one shows its own physical address.

For a cleaner view of just MAC addresses and adapter names:

getmac /v /fo list

Settings method. Go to Settings > Network & Internet > Wi-Fi (or Ethernet). Click your connected network and scroll to Physical address (MAC). On Windows 11, the path is Settings > Network & internet > Wi-Fi > Hardware properties.

macOS

System Settings method. Open System Settings > Network. Select your connection, then click Details. The MAC address appears as “Wi-Fi Address” or “Hardware (MAC) Address.”

Terminal method:

ifconfig en0 | grep ether

Use en0 for the primary interface, usually Wi-Fi. Use en1 for a secondary interface. The output shows the MAC address on the ether line.

Linux

The modern approach uses the ip command:

ip link show

This lists every interface with its MAC address on the link/ether line. To show only one interface:

ip link show eth0

The older ifconfig command also works if it is installed:

ifconfig eth0 | grep ether

iOS (iPhone and iPad)

Go to Settings > General > About. The “Wi-Fi Address” field shows the MAC address. Since iOS 14, Apple uses a private Wi-Fi address for each network by default. So the address shown here may differ from what your router sees. To view or change it, open Settings > Wi-Fi and tap the info button next to your network.

Android

Go to Settings > About Phone > Status > Wi-Fi MAC address. On some versions, the path is Settings > Network & Internet > Wi-Fi, then tap your network and open Advanced. Like iOS, Android 10 and later randomize MAC addresses per network by default.

From Your Router Admin Page

Log into your router, usually at 192.168.1.1 or 192.168.0.1. Open the connected devices or DHCP client list. This shows the MAC address of every connected device. It is the easiest way to find the MAC of a device with no screen, like an IoT sensor.

What Is a MAC Address Used For?

MAC addresses make local networks work. Switches use them to forward frames to the right port. Administrators use them for DHCP reservations and basic MAC filtering. OUI lookups help identify and inventory devices. Wake-on-LAN uses a MAC address to power on a sleeping computer remotely.

MAC addresses are fundamental to how local networks function. Here are the primary use cases.

Network switching. When a switch receives a frame, it reads the destination MAC address. It then forwards the frame only to the port where that MAC was last seen. The switch keeps a MAC address table (a CAM table) mapping addresses to ports. Without it, every frame would broadcast to every port.

DHCP reservations. Administrators map a MAC address to a fixed IP via DHCP. A reservation means your printer always gets 192.168.1.50. You avoid configuring a static IP on the device itself. This helps devices that need stable addresses for DNS records or firewall rules. For the full handshake behind that lease, see our guide on how DHCP works.

MAC address filtering. Many routers support an allow-list or deny-list of MAC addresses. It is not strong security, since MAC addresses can be spoofed. But it adds a basic access layer for home networks. For real protection, see our guide on what is a firewall.

Device identification. On enterprise networks, MAC addresses help inventory and track devices. Combined with OUI lookups, admins can spot rogue hardware and enforce access policies. This is often the first step in troubleshooting network connectivity issues, and it’s exactly the workflow our guide on identifying an unknown device on your network walks through end to end, from router client list to confirmed vendor. If your network is segmented, our guide on spotting an out-of-place MAC vendor on a VLAN covers the same check for a locked-down segment.

Wake-on-LAN (WoL). This protocol powers on a remote computer with a special magic packet. The packet contains the target MAC address repeated 16 times. The network card listens for this pattern even while the computer is off. A matching packet triggers a boot.

Can a MAC Address Be Changed?

Yes. The MAC address is burned into hardware, but the address your system uses can be changed in software. This is called MAC spoofing. People do it for privacy, to bypass MAC filtering, or to clone a router for an ISP. Because spoofing is so easy, a MAC address is never a reliable credential.

Yes. The MAC address is burned into hardware. But the address your operating system actually uses can be overridden in software. This is called MAC spoofing or MAC cloning.

On Windows, change it through Device Manager. Open the adapter properties and go to the Advanced tab. Find the Network Address or Locally Administered Address field. Enter a new value there. From an elevated command prompt, you can also run:

netsh interface set interface "Wi-Fi" newmac=02:11:22:33:44:55

On Linux, three commands do it:

sudo ip link set dev eth0 down
sudo ip link set dev eth0 address 02:11:22:33:44:55
sudo ip link set dev eth0 up

On macOS:

sudo ifconfig en0 ether 02:11:22:33:44:55

Why people change their MAC address:

• Privacy. Preventing tracking across Wi-Fi networks by retailers, airports, and advertisers that watch probe requests.
• Bypassing MAC filtering. Reaching a network that only allows pre-approved MAC addresses. This is why MAC filtering alone is weak security.
• ISP cloning. Some ISPs bind your connection to a router or modem MAC. When you swap hardware, cloning the old MAC avoids a re-registration wait.
• Testing and development. Engineers change MAC addresses to simulate devices, test switch behavior, or troubleshoot in lab environments.

Security implications. Because MAC addresses change so easily, never treat them as authentication. MAC filtering can deter casual freeloaders. But any attacker who can watch traffic sees legitimate MAC addresses. They can clone one in seconds.

MAC Address Privacy and Security

Because a MAC address can identify a device across visits, it is a tracking risk. Modern phones and computers now randomize the Wi-Fi MAC address by default. Apple, Google, and Microsoft each ship this feature. A MAC address is also visible to anyone on the local segment. Treat it as an identifier, not a secret.

For years, the static MAC address created a privacy problem. When your phone scanned for Wi-Fi, it broadcast its real MAC in probe request frames. This happened even without connecting. Retailers and analytics firms deployed sensors to collect these probes. They built movement profiles and foot-traffic data from MAC addresses.

The industry response is MAC address randomization, now a default in every major OS. The exact behavior has matured since the first releases:

• iOS 18 and iPadOS 18 (2024): Apple replaced the old on/off toggle with three settings — Off, Fixed, and Rotating. The default is Fixed on WPA2 or stronger networks. The default is Rotating on weak or open networks, where the address changes every two weeks.
• macOS Sequoia 15 (2024): Brings the same Off, Fixed, and Rotating model to the Mac. Earlier macOS Sonoma added private Wi-Fi addresses, but without the three-way control.
• Android 10+ (2019): Randomizes a persistent MAC per network by default. Android 12 added non-persistent (per-connection) randomization for some networks.
• Windows 10 and 11: Offers “Random hardware addresses” in Wi-Fi settings, per network or for all networks.

What this means for administrators. Randomization complicates several traditional techniques. DHCP reservations tied to a MAC can break when a device picks a new random address. MAC-based access control becomes unreliable. Inventory tools may see one phone as several devices over time.

The practical fix for enterprises is 802.1X authentication (RADIUS-based access control). It identifies devices without trusting the MAC address. Some home networks need a stable MAC for a DHCP reservation. For those, you can disable randomization on that one network. Understand that doing so re-enables tracking on that connection.

From a security standpoint, a MAC address is visible to anyone on the same local network. Layer 2 headers travel in cleartext on the local segment, unlike encrypted IP payloads. So never use a MAC address as a secret or credential. It is an identifier, not an authenticator.

Related Tools & Resources

Put this into practice with our free networking tools. Look up any MAC address vendor, check your public IP address, or inspect DNS records in seconds. Each tool runs in your browser, with nothing to install. The guides below explain the concepts behind every tool.

• MAC Address Vendor Lookup — paste any MAC address and identify the hardware manufacturer from its OUI.
• What Is My IP Address — see your public IP address and basic location details.
• DNS Lookup — inspect the DNS records for any domain.
• OSI Model Explained — understand the seven layers, including where MAC addresses live.
• How to Troubleshoot Network Connectivity — a step-by-step diagnostic walkthrough.

Frequently Asked Questions

Short answers to the questions people ask most about MAC addresses. These cover what MAC means and how it differs from a physical address. They also explain why your phone shows a new MAC on each network.