MAC Address Lookup: Find the Manufacturer from Any MAC Address

What Is a MAC Address?

A Media Access Control (MAC) address is a unique hardware identifier assigned to every network interface card (NIC). It operates at Layer 2 (Data Link Layer) of the OSI model and is used for local network communication. While IP addresses identify devices logically and can change, MAC addresses are typically burned into hardware by the manufacturer.

MAC Address Structure

A MAC address is 48 bits (6 bytes) long, displayed in hexadecimal:

• Colon-separated: AA:BB:CC:DD:EE:FF
• Dash-separated (Windows): AA-BB-CC-DD-EE-FF
• Cisco format: AABB.CCDD.EEFF

OUI (Organizationally Unique Identifier)

The first 3 bytes (24 bits) are the OUI — assigned by IEEE to each manufacturer. By looking up the OUI, you can identify who made the network hardware:

• Apple, Inc.
• VMware (indicating virtualized hardware)
• Raspberry Pi Foundation
• Intel Corporate
• Cisco Systems

Device Identifier

The last 3 bytes are assigned by the manufacturer to uniquely identify each device. Together, the full 48-bit address creates a globally unique identifier for the network interface.

MAC Address Types

Unicast vs. Multicast

• Unicast (LSB of first byte = 0): Identifies a single network interface
• Multicast (LSB of first byte = 1): Targets a group of devices
• Broadcast (FF:FF:FF:FF:FF:FF): Reaches all devices on the segment

Common multicast addresses include IPv4 and IPv6 multicast ranges.

Universally Administered (UAA) vs. Locally Administered (LAA)

• UAA (second bit of first byte = 0): Manufacturer-assigned, globally unique
• LAA (second bit of first byte = 1): Locally assigned, may not be globally unique

Random/Spoofed MAC Addresses

Modern devices randomize MAC addresses for privacy (iOS 14+, Android 10+, Windows 10+). These locally administered addresses prevent tracking across different networks and locations.

Finding MAC Addresses

On different platforms:

• Windows: ipconfig /all or getmac /v
• macOS/Linux: ifconfig or ip link show
• Network scan: arp -a shows the ARP cache, mapping IPs to MACs on your local network

MAC Address Security Considerations

ARP Spoofing

Attackers can send fake ARP responses to associate their MAC address with another device's IP. This enables man-in-the-middle attacks and traffic interception. Defense: Dynamic ARP Inspection (DAI) on managed switches.

MAC Flooding

Flooding a switch's MAC address table with fake addresses, causing it to behave like a hub and broadcast all traffic. Defense: port security limiting MAC addresses per port.

MAC Filtering

Using MAC addresses as an access control mechanism has significant weaknesses — MAC addresses can be trivially spoofed, making MAC filtering an unreliable security measure on its own.

Using the MAC Address Lookup Tool

Our MAC address lookup tool provides:

1. OUI Identification — Enter any MAC address to identify the manufacturer
2. Bulk Lookup — Process multiple MAC addresses at once
3. Format Detection — Accepts colons, dashes, dots, or no separators
4. Company Details — Full registered company name
5. Device Classification — Identify virtual adapters, IoT devices, phones, and PCs

Useful for network administrators investigating unknown devices on their network, security audits to identify unauthorized hardware, and network inventory documentation.

MAC vs. IP Address Summary

Understanding the relationship between MAC and IP addresses is fundamental to network troubleshooting and security analysis.