What is the locally administered (LA) bit?

Bit 1 (second-least-significant) of the first octet. When set to 1 the address is locally administered — meaning it was assigned by software rather than burned into hardware by a manufacturer. Virtual machines, VPN adapters, and Docker networks use locally-administered MACs.

What is the multicast bit?

Bit 0 (least-significant) of the first octet. When set to 1, frames sent to this address are delivered to a group of network interfaces rather than a single device. Broadcast (FF:FF:FF:FF:FF:FF) is the all-ones special case of a multicast address.

Are generated addresses assigned to real hardware?

No. The bytes are cryptographically random. When the globally-unique (LA=OFF) mode is used, the OUI portion might coincidentally match a registered vendor prefix, but the full 48-bit address is not allocated to any device.

What is the difference between the three delimiter formats?

All three encode the same 48-bit value. Colon (AA:BB:CC:DD:EE:FF) is standard on Linux and macOS. Hyphen (AA-BB-CC-DD-EE-FF) is common on Windows. Dot/IEEE (AABB.CCDD.EEFF) groups bytes into three 16-bit pairs and is used in Cisco IOS output.

Can I use these MACs in production?

Only for virtual or test environments. Locally-administered MACs (LA=ON) are designed for this purpose. Using a randomly generated globally-unique MAC on a live network may cause an address collision and should be avoided.

Random MAC Address Generator

Name: Random MAC Address Generator
Availability: InStock
Author: Nham Vu

Generate random MAC addresses with control over delimiter format, letter case, and locally-administered / multicast bit flags.

Delimiter Format

AA:BB:CC:DD:EE:FF Colon AA-BB-CC-DD-EE-FF Hyphen AABB.CCDD.EEFF Dot (IEEE)

Letter Case

AA:BB aa:bb

First-Octet Bit Flags

Locally Administered (LA)

Bit 1 of first octet

Multicast (MC)

Bit 0 of first octet

Quantity 10

1200

Generated Addresses

Click Generate to create MAC addresses

Copied!

Summary

Generate random MAC addresses with control over delimiter format, letter case, and locally-administered / multicast bit flags.

How it works

Choose a delimiter: colon (AA:BB:CC:DD:EE:FF), hyphen (AA-BB-CC-DD-EE-FF), or dot (AABB.CCDD.EEFF).
Select letter case: uppercase (AA:BB) or lowercase (aa:bb).
Set the Locally Administered bit: ON marks the address as software-assigned; OFF means the tool generates a globally unique OUI-compatible prefix.
Set the Multicast bit: ON makes the address a multicast/broadcast destination; OFF keeps it unicast.
Enter how many addresses you need (1–200) and click Generate.
Copy individual addresses, copy all, or download as a plain-text file.

Use cases

Populate test databases with syntactically valid MAC addresses.
Generate locally-administered unicast MACs for virtual network interfaces.
Test MAC address parsing and validation logic in application code.
Create dummy DHCP lease or ARP table entries for documentation.
Simulate network topologies in lab or CI environments.
Generate multicast group addresses for streaming protocol testing.
Verify UI components that display or accept hardware identifiers.
Produce bulk address lists for load-testing network management software.

Frequently Asked Questions

Related tools

Fake Mac Address Generator Fake Ip Address Generator Encryption Key Generator

Last updated: 2026-05-28 · Reviewed by Nham Vu