Generate random MAC addresses with custom prefixes, casing, and separator formats.
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About MAC address generator
Generates random 48-bit MAC addresses, up to 1000 at a time, using crypto.getRandomValues. You can set a vendor OUI prefix (with presets), choose colon, hyphen, dot or no separator, and pick upper or lower case. Without a prefix you can control the locally administered and unicast/multicast bits of the first octet.
Common uses
- Assign MAC addresses to virtual machines or containers
- Create test data for network inventory or DHCP tools
- Generate addresses with a specific vendor prefix for testing
- Produce MAC addresses in the format a particular system expects
FAQ
- What is a locally administered MAC address?
- It is an address with the U/L bit (second-least significant bit of the first octet) set to 1. It is not assigned by a manufacturer, so it is the safe choice for VMs and testing because it will not clash with a real vendor's range.
- What is the difference between unicast and multicast MAC addresses?
- The least significant bit of the first octet is the I/G bit. When it is 0 the address is unicast (one interface); when it is 1 it is a multicast or group address.
- What is an OUI?
- The Organizationally Unique Identifier is the first 3 bytes of a MAC address, assigned by the IEEE to a manufacturer. The remaining 3 bytes are assigned by the vendor.