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

Every network device you own — your laptop, phone, smart TV, game console, even your wireless printer — has at least one MAC address burned into its hardware. It’s the foundational identifier that makes local networking work: when your laptop sends a packet to your router, the router knows which device sent it because of the MAC address, not the IP address.

Yet most people never encounter their MAC address until they need to set up MAC filtering on a router, reserve a DHCP address for a device, troubleshoot a network issue, or register a device on a corporate or university network. This guide explains what a MAC address is, how it differs from an IP address, how to find yours on any device, and what you should know about MAC address privacy and security.

What Is a MAC Address?

A MAC address (Media Access Control address) is a unique identifier assigned to a network interface controller (NIC) for use as a network address in communications within a network segment. It operates at Layer 2 of the OSI model — the data link layer — which means it’s used for communication between devices on the same local network, before IP routing even enters the picture.

Every MAC address is 48 bits long (6 bytes), written as six groups of two hexadecimal digits. You’ll 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’s firmware during manufacturing, which is why it’s sometimes called a hardware address, physical address, or burned-in address (BIA). Every Ethernet port, Wi-Fi adapter, and Bluetooth radio on a device has its own distinct MAC address. A laptop with both Ethernet and Wi-Fi has at least two MAC addresses.

The 48-bit address space yields approximately 281 trillion possible combinations (2⁴⁸ = 281,474,976,710,656), which is large enough that the IEEE can continue assigning unique blocks to manufacturers for the foreseeable future.

MAC Address vs IP Address

People frequently confuse MAC addresses and IP addresses because both are “addresses” associated with network devices. But they serve fundamentally different purposes and operate at different layers of the network stack.

Here’s the key relationship: when your computer wants to send data to another device on the same subnet, it uses the ARP protocol (Address Resolution Protocol) to translate the destination IP address into a MAC address. The actual Ethernet frame that travels over the wire or Wi-Fi carries the MAC address — the IP address is encapsulated inside the payload. Without the MAC address, the frame wouldn’t reach the right device.

What Is an OUI?

The first three octets (24 bits) of a MAC address are called the OUI — Organizationally Unique Identifier. This portion identifies the manufacturer or vendor that produced the network interface. The remaining three octets are assigned by the manufacturer to individual devices, ensuring uniqueness within their allocated block.

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

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

The IEEE (Institute of Electrical and Electronics Engineers) manages OUI registration through its Registration Authority. Manufacturers purchase OUI blocks from the IEEE, 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 identify the vendor.

An OUI lookup is genuinely useful in network administration. If you see an unknown device on your network with the MAC address DC:A6:32:xx:xx:xx, an OUI lookup reveals it’s a Raspberry Pi. If you spot 00:50:56:xx:xx:xx, that’s a VMware virtual machine. This helps you quickly identify devices, detect unauthorized hardware, and inventory your network without physically inspecting every connected device.

The IEEE also offers smaller blocks — MA-M (28-bit identifiers) and MA-S (36-bit identifiers) — for manufacturers that don’t need a full 16 million device addresses from a standard OUI allocation.

How to Find Your MAC Address

The process for finding your MAC address differs by operating system. Here are specific 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 network adapter (Ethernet or Wi-Fi). The value will look like A4-83-E7-2F-5B-10. If you have multiple adapters, you’ll see a physical address listed for each one.

For a cleaner view showing only MAC addresses and adapter names:

getmac /v /fo list

Settings method (Windows 10) — go to Settings > Network & Internet > Wi-Fi (or Ethernet) > click your connected network > scroll down 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 (Wi-Fi or Ethernet) > click Details (or Advanced on older versions). The MAC address appears labeled as “Wi-Fi Address” or “Hardware (MAC) Address.”

Terminal method:

ifconfig en0 | grep ether

Use en0 for the primary interface (usually Wi-Fi) and en1 for a secondary interface. The output shows the MAC address on the line starting with ether.

Linux

The modern approach uses the ip command:

ip link show

This lists all network interfaces with their MAC addresses on the link/ether line. To show only a specific interface:

ip link show eth0

The older ifconfig command also works if installed:

ifconfig eth0 | grep ether

iOS (iPhone and iPad)

Go to Settings > General > About. The “Wi-Fi Address” field shows the MAC address. Note that starting with iOS 14, Apple uses a private Wi-Fi address (a randomized MAC) for each network by default, so the address shown here may differ from what your router sees. To view or toggle this, go to Settings > Wi-Fi > tap the info (i) button next to your network > look for “Private Wi-Fi Address.”

Android

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

From Your Router Admin Page

Log into your router (typically at 192.168.1.1 or 192.168.0.1) and navigate to the connected devices or DHCP client list. This shows the MAC address of every device currently connected to your network — useful when you need to find the MAC address of a device that doesn’t have an easy settings menu, like an IoT sensor or smart plug.

What Is a MAC Address Used For?

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

Network switching. When a switch receives a frame, it reads the destination MAC address and forwards the frame only to the port where that MAC address was last seen. The switch maintains a MAC address table (also called a CAM table) that maps MAC addresses to physical ports. This is the core mechanism that makes switched Ethernet efficient — without MAC addresses, every frame would have to be broadcast to every port.

DHCP reservations. Network administrators use MAC addresses to assign a consistent IP address to a specific device via DHCP. By creating a reservation that maps a MAC address to a particular IP, you ensure that your network printer always gets 192.168.1.50 without configuring a static IP on the device itself. This is essential for devices that need stable addresses for DNS records or firewall rules.

MAC address filtering. Some routers and wireless access points support MAC filtering, which creates an allow-list or deny-list of MAC addresses that can connect to the network. While not a strong security measure (since MAC addresses can be spoofed), it adds a basic layer of access control for home networks. For stronger network protection, see our guide on what is a firewall.

Device identification. On enterprise networks, MAC addresses help network management systems inventory and track devices. Combined with OUI lookups, administrators can identify device types, detect rogue hardware, and enforce network access control (NAC) policies. When unknown devices appear, this is often the first step in troubleshooting network connectivity issues.

Wake-on-LAN (WoL). This protocol allows you to power on a remote computer by sending a specially crafted “magic packet” that contains the target device’s MAC address repeated 16 times. The network card listens for this pattern even when the computer is in a powered-off state and triggers a boot sequence when it receives a matching packet.

Can a MAC Address Be Changed?

Yes. Even though the MAC address is burned into hardware, the address your operating system actually uses on the network can be overridden in software. This is called MAC spoofing or MAC cloning.

On Windows, you can change the MAC address through Device Manager: open the properties of your network adapter > Advanced tab > look for “Network Address” or “Locally Administered Address” > enter a new value. Alternatively, from an elevated command prompt:

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

On Linux, it’s straightforward:

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 different Wi-Fi networks by retailers, airports, and advertisers that monitor probe requests.
• Bypassing MAC filtering. Gaining access to a network that restricts connections to pre-approved MAC addresses (this is why MAC filtering alone is not reliable security).
• ISP cloning. Some ISPs bind your internet connection to the MAC address of your original router or modem. When replacing hardware, you may need to clone the old device’s MAC address to avoid waiting for the ISP to re-register the new one.
• Testing and development. Network engineers routinely change MAC addresses to simulate multiple devices, test switch behavior, or troubleshoot network issues in lab environments.

Security implications: Because MAC addresses can be changed trivially, they should never be treated as a reliable authentication mechanism. MAC filtering can deter casual freeloaders, but any attacker who can observe network traffic can see the MAC addresses of legitimate devices and clone one in seconds.

MAC Address Privacy and Security

For years, the static nature of MAC addresses created a serious privacy problem. When your phone scanned for available Wi-Fi networks, it broadcast its real MAC address in probe request frames — even without connecting to any network. Retailers, shopping malls, and advertising companies deployed sensors to passively collect these probe requests, building movement profiles and foot traffic analytics based on MAC addresses.

The industry response has been MAC address randomization, now a default feature in every major operating system:

• iOS 14+ (2020): Generates a unique “private Wi-Fi address” for each network. The randomized MAC persists for that specific network but differs from the hardware MAC and from the address used on other networks.
• Android 10+ (2019): Uses randomized MAC addresses per network by default. Android 12 added per-connection randomization as an option.
• Windows 10/11: Offers “Random hardware addresses” in Wi-Fi settings, with options for per-network or global randomization.
• macOS Sonoma+ (2023): Added private Wi-Fi address support, generating a unique MAC for each network similar to iOS.

What this means for network administrators: MAC randomization complicates several traditional network management techniques. DHCP reservations tied to MAC addresses may break when a device generates a new random address. MAC-based access control lists become unreliable. Device inventory tools that track devices by MAC address may see the same phone appear as multiple different devices over time.

The practical workaround for enterprise environments is to use 802.1X authentication (RADIUS-based network access control) instead of relying on MAC addresses for device identification. For home networks where you need a stable MAC for a DHCP reservation, you can disable randomization for that specific network in the device’s Wi-Fi settings — but understand that doing so re-enables tracking for that connection.

From a security standpoint, remember that a MAC address is visible to anyone on the same local network. Unlike IP traffic, which can be encrypted end-to-end, Layer 2 headers (including MAC addresses) are always transmitted in cleartext on the local segment. This means you should never use a MAC address as a secret or credential — it’s an identifier, not an authenticator.

Frequently Asked Questions