MAC Address Generator

Generate random, vendor-prefixed, or bulk MAC addresses. Validate existing MACs. Supports colon, hyphen, and Cisco dot notation.

Generated MAC Address(es)
Click Generate to create a MAC address.

How to Use the MAC Address Generator

  1. Choose a mode — select Random for a fully random MAC, Vendor OUI to fix the first 3 bytes to a known manufacturer prefix, Bulk to generate multiple MACs at once, or Validate to check an existing MAC address.
  2. Pick a format — colon-separated (AA:BB:CC:DD:EE:FF) is the Linux/macOS standard, hyphen-separated (AA-BB-CC-DD-EE-FF) is used by Windows, and Cisco dot notation (AABB.CCDD.EEFF) is used in Cisco IOS commands.
  3. Set bit flags — optionally force the Locally Administered Bit (bit 1 of first octet) or the Multicast bit (bit 0) to match specific network scenarios.
  4. Click Generate — your MAC address(es) appear instantly in the output panel.
  5. Copy or download — click Copy to send the output to your clipboard, or Download to save as a plain-text file.

Understanding MAC Addresses

A MAC address (Media Access Control address) is a 48-bit hardware identifier assigned to every network interface in every device that communicates over Ethernet, Wi-Fi, Bluetooth, or other IEEE 802 standards. The address is composed of 6 octets (bytes) written in hexadecimal, totalling 12 hex digits. The format is standardized by IEEE 802 and is critical for local network communication at Layer 2 of the OSI model.

OUI: The Vendor Identifier

The first three octets of a MAC address form the OUI (Organizationally Unique Identifier). The IEEE assigns OUI blocks to hardware manufacturers, allowing network engineers to identify which company made a network card just from the address. For example, if you see a MAC starting with 00:17:F2, that device was manufactured by Apple. OUI lookups are used in network security audits, inventory management, and troubleshooting. This tool lets you generate MACs with real-world OUI prefixes from vendors including Apple, Intel, Dell, Cisco, Samsung, VMware, and Raspberry Pi.

The Two Special Bits

The first octet of a MAC address encodes two control bits:

  • Bit 0 (LSB) — Unicast/Multicast: When 0, the frame is addressed to a single device (unicast). When 1, the frame targets a group (multicast). The broadcast address FF:FF:FF:FF:FF:FF has all bits set, including this one.
  • Bit 1 — Global/Local: When 0, the address is globally administered — burned into the hardware by the manufacturer under IEEE oversight. When 1, the address is locally administered, meaning it was manually configured or randomly assigned (common in VMs, containers, and privacy-focused MAC randomization on modern operating systems).

MAC Address Formats

The three most common notations all represent the same 48 bits:

  • Colon-separated (AA:BB:CC:DD:EE:FF) — the standard on Linux, macOS, Android, and most Unix-based tools. Each octet is separated by a colon.
  • Hyphen-separated (AA-BB-CC-DD-EE-FF) — used by Windows (ipconfig /all output), and common in documentation and configuration files.
  • Cisco dot notation (AABB.CCDD.EEFF) — used in Cisco IOS commands like show mac address-table. Octets are grouped into three 16-bit pairs separated by dots.

Common Use Cases

  • Network lab simulation — generate realistic MAC addresses for GNS3, EVE-NG, or Packet Tracer virtual network labs.
  • Virtual machine configuration — assign custom MACs to VirtualBox, VMware, or KVM virtual network adapters to avoid conflicts.
  • Network security testing — test MAC filtering rules and ACLs without risking production hardware addresses.
  • DHCP reservation testing — generate test MACs for DHCP static assignment entries in router and server configurations.
  • Software development — populate test data for applications that record or display device identifiers.
  • Documentation — create example MAC addresses for network diagrams, wikis, and runbooks without exposing real hardware addresses.

MAC Address Validation

This tool's Validate mode checks whether an address is syntactically valid: 6 octets of hexadecimal digits in colon, hyphen, or Cisco dot notation. It also reports the address's unicast/multicast status, global/local administration flag, and attempts to identify the vendor from the first 3 bytes. Valid address detection is useful when reviewing device logs, network captures, or user-entered configuration data where format errors are common. For related network tools, see our IP Subnet Calculator and CIDR Calculator.

Frequently Asked Questions

A MAC (Media Access Control) address is a 48-bit hardware identifier assigned to a network interface controller (NIC). It is represented as 6 pairs of hexadecimal digits (e.g., AA:BB:CC:DD:EE:FF) and is used at the data-link layer of the OSI model to uniquely identify devices on a local network segment. The first 3 bytes (OUI) identify the vendor, and the last 3 bytes are assigned by the manufacturer.
The OUI (Organizationally Unique Identifier) is the first 3 bytes (24 bits) of a MAC address. It is assigned by the IEEE to hardware manufacturers and uniquely identifies the vendor. For example, Apple's OUI block includes prefixes like 00:17:F2, Intel uses prefixes like 00:1B:21, and Cisco uses prefixes like 00:1A:2B. Knowing the OUI lets network administrators identify which vendor manufactured a device.
A locally administered address (LAA) is a MAC address where bit 1 of the first octet is set to 1. This indicates the address was manually configured rather than burned in by the hardware manufacturer. LAAs are commonly used in virtualization (virtual machines, containers) and MAC randomization for privacy. In contrast, a globally administered address (GAA) has bit 1 set to 0 and was assigned by the IEEE via a hardware manufacturer.
Unicast MAC addresses (bit 0 of the first octet = 0) are intended for a single recipient. Multicast MAC addresses (bit 0 of the first octet = 1) are intended for a group of recipients. The broadcast address FF:FF:FF:FF:FF:FF is a special multicast address that reaches all devices on a segment. Network hardware uses the multicast bit to decide whether to pass a frame to the CPU or handle it in firmware.
There are three common notations: Colon-separated (AA:BB:CC:DD:EE:FF) — used by Linux, macOS, and most Unix tools; Hyphen-separated (AA-BB-CC-DD-EE-FF) — used by Windows and common in documentation; Dot-separated (AABB.CCDD.EEFF) — used by Cisco IOS, grouping octets in pairs. All three represent the same 48-bit value; the choice is purely a display convention.