MAC Address Generator
Generate random MAC addresses for testing and development. Choose your preferred format and generate multiple addresses at once.
How to Generate MAC Addresses
Step 1: Choose Format
Select your preferred format: colon-separated (Unix/Linux), dash-separated (Windows), Cisco notation, or raw hex.
Step 2: Configure Options
Keep unicast mode enabled for valid device addresses. Disable for multicast address testing.
Step 3: Generate and Copy
Generate addresses and copy them for network testing, device simulation, or database seeding.
Understanding MAC Addresses
A MAC (Media Access Control) address is a 48-bit identifier assigned to network interfaces. It's used at the data link layer for local network communication.
Our generator creates locally administered addresses (LAA) which are safe to use for testing without conflicting with manufacturer-assigned addresses.
MAC Address Bits
- Bit 0 (LSB of byte 1): Unicast (0) or Multicast (1)
- Bit 1: Globally unique (0) or Locally administered (1)
- Bytes 1-3: OUI (vendor identifier)
- Bytes 4-6: Network interface identifier
Frequently Asked Questions
What is a locally administered MAC address?
A locally administered address (LAA) has the second bit set to 1, indicating it was assigned locally rather than by a manufacturer. These are safe for testing because they don't conflict with real device OUIs.
Can I use these on real networks?
Yes, for testing in isolated environments. MAC address spoofing is used for network testing, privacy, and device simulation. However, be aware of network policies and legal considerations.
Which format should I use?
Colon format is standard on Unix/Linux, dash format on Windows. Cisco uses dot notation in groups of 4. Choose based on your target system or tool requirements.
What's the difference between unicast and multicast?
Unicast addresses identify single devices (LSB of first byte = 0). Multicast addresses target multiple devices (LSB = 1). Most testing needs unicast addresses.
Are MAC addresses globally unique?
Manufacturer-assigned MACs should be globally unique via the OUI system. Locally administered addresses (like ours) are not globally unique but are valid for local use.
Common MAC address use cases
- Network device simulation and testing
- Virtual machine configuration
- Docker container networking
- IoT device testing
- Network access control testing
- DHCP reservation testing