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▶ Developer Tools for Random Data Generation // v2.1.2
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Random MAC Address Generator

Generate random MAC addresses for network testing and virtual machines

Our random MAC address generator helps you generate random MAC addresses for network testing and virtual machine configuration. Generate-Random.org provides a free MAC address generator that creates standard MAC-48 addresses with multiple format options including colon-separated, hyphen-separated, dot-separated, and Cisco formats. This CSPRNG MAC generator uses cryptographically secure random number generation for maximum security—perfect for network testing, virtual machines, network simulations, and development environments. Generate up to 100 MAC addresses instantly with IEEE 802 compliance. No signup required, completely free.

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What is a MAC Address Generator?

A MAC Address Generator creates random Media Access Control (MAC) addresses for network device identification and testing. Our generator uses cryptographically secure random number generation to ensure truly random MAC-48 addresses that comply with IEEE 802 standards.

MAC addresses are 48-bit identifiers (6 octets) assigned to network interfaces, typically displayed as hexadecimal values separated by colons (00:1A:2B:3C:4D:5E), hyphens, or dots. They're essential for network layer communication and device identification. For other network testing needs, try our IP address generator.

MAC Address Generator Configuration Options

Format Selection (Colon / Hyphen / Dot / None)

Choose separator style: Colon (00:1A:2B:3C:4D:5E) is the standard format, Hyphen (00-1A-2B-3C-4D-5E) is Windows style, Dot (00.1A.2B.3C.4D.5E) is used by some vendors, or None (001A2B3C4D5E) for compact representation.

Separator Style (Full / Cisco)

Full format separates each octet (XX:XX:XX:XX:XX:XX), while Cisco format groups octets in pairs (XXXX.XXXX.XXXX). Both represent the same MAC address with different notation commonly used by different network equipment vendors.

Case (Uppercase / Lowercase)

Generate addresses in uppercase (00:1A:2B:3C:4D:5E) or lowercase (00:1a:2b:3c:4d:5e) hexadecimal. Most systems accept both, but some applications may require specific casing for consistency.

Quantity (1-100 MAC Addresses)

Generate between 1 and 100 MAC addresses in a single batch for configuring multiple virtual machines, testing network equipment, or populating test databases. Each address is independently generated with full cryptographic randomness.

Locally Administered Addresses

Enable to generate locally administered addresses (bit 1 of first octet set to 1, e.g., 02:XX:XX:XX:XX:XX). These are commonly used for virtual machines and containers. Disable for globally unique addresses assigned by manufacturers.

Multicast Addresses

Control whether multicast addresses are generated (bit 0 of first octet set to 1). Unicast addresses (default) are for individual devices, while multicast addresses are for group communications.

How to Generate Random MAC Addresses

[STEP 1] Choose Format

Select separator type: colon (:), hyphen (-), dot (.), or no separator. Choose Cisco format if needed for network equipment compatibility.

[STEP 1] Set Case and Quantity

Choose uppercase or lowercase hexadecimal. Set how many MAC addresses to generate (1-100).

[STEP 1] Configure Options

Enable locally administered addresses for VMs or multicast addresses if needed for your testing scenario.

[STEP 1] Generate & Export

Click generate and copy individual addresses or export all to TXT, CSV, or JSON format for bulk operations.

Common Use Cases for Random MAC Addresses

  • _ Virtual Machine Configuration - Assign unique MAC addresses to VMs for proper network identification and DHCP allocation
  • _ Network Testing - Test network equipment, switching logic, and MAC filtering rules with diverse addresses
  • _ Network Simulation - Simulate multiple network devices for capacity testing and network behavior analysis
  • _ IoT Development - Generate MAC addresses for IoT device simulation, testing, and prototyping
  • _ Container Networking - Assign unique MAC addresses to containers for network isolation and routing
  • _ Test Data Generation - Populate databases and logs with realistic MAC addresses for testing and development

Technical Details: MAC Address Generation Algorithm

Our MAC address generator employs cryptographically secure random number generation to create valid MAC-48 addresses following IEEE 802 standards. The system properly handles unicast/multicast and global/local administration bits, validates address structure, and supports multiple format representations used by different network vendors.

// MAC-48 Address Structure (48 bits / 6 octets)
OUI (Organizationally Unique Identifier): 24 bits
NIC (Network Interface Controller): 24 bits

// First Octet Special Bits
Bit 0 (LSB): Unicast (0) vs Multicast (1)
Bit 1: Globally unique (0) vs Locally administered (1)

// Example: 00:1A:2B:3C:4D:5E
00 = 0000 0000 binary (both bits 0 = unicast, globally unique)
1A:2B:3C = Remaining OUI bits
4D:5E = NIC specific bits

Algorithm: CSPRNG-Based MAC Generation
For each MAC address:
  1. Generate 6 random bytes (48 bits)
  2. Set bit 0 for unicast/multicast
  3. Set bit 1 for global/local administration
  4. Format based on separator style
  5. Apply case transformation
  6. Validate IEEE 802 compliance

Security: NIST SP 800-90A compliant CSPRNG
Standards: IEEE 802 MAC-48 format

API Access for Developers

GET https://generate-random.org/api/v1/generate/mac-addresses
VIEW FULL API DOCUMENTATION →

Frequently Asked Questions

What is a MAC address? ▶
A MAC (Media Access Control) address is a unique 48-bit identifier assigned to network interfaces for communication at the data link layer. It consists of 6 octets (bytes) typically displayed as hexadecimal values separated by colons, hyphens, or dots. Example: 00:1A:2B:3C:4D:5E.
What's the difference between colon and Cisco format? ▶
Standard colon format separates each octet (00:1A:2B:3C:4D:5E), while Cisco format groups octets in pairs separated by dots (001A.2B3C.4D5E). Both represent the same MAC address, just in different notations commonly used by different network equipment vendors.
What are locally administered addresses? ▶
Locally administered addresses have bit 1 of the first octet set to 1, indicating the address is not globally unique and was assigned locally by an administrator. These are commonly used for virtual machines and containers. Example: 02:XX:XX:XX:XX:XX or X2, X6, XA, XE in the first octet.
Can I use these MAC addresses in production? ▶
These addresses are intended for testing, development, and non-production environments. For production use, obtain officially assigned MAC addresses from the IEEE Registration Authority to ensure global uniqueness and avoid conflicts. For testing network configurations, our generator is perfect.
How are MAC addresses generated securely? ▶
Our generator uses PHP's random_int() function with CSPRNG (Cryptographically Secure Pseudo-Random Number Generator) to generate each octet. This ensures true randomness and prevents predictable patterns. The generator also respects IEEE 802 standards for unicast/multicast and global/local address bits.