Developer

MAC Address Tools

Validate, format and generate MAC addresses, look up the vendor from an OUI table, and decode the U/L and I/G bit flags.

MAC addressValid

Examples

Formats

ColonFC:FB:FB:01:02:03
HyphenFC-FB-FB-01-02-03
Dot (Cisco)FCFB.FB01.0203
BareFCFBFB010203

Analysis

Flags

Unicast (I/G bit clear)
Universally administered (U/L bit clear)

Vendor (OUI)

Cisco Systems, Inc.

Generate a random MAC

Locally administeredSets the U/L bit so the address won't clash with a vendor.UnicastClears the I/G bit to produce a unicast address.

About MAC addresses

A MAC address (EUI-48) is a 48-bit value identifying a network interface. The two lowest bits of the first octet set the address type: the I/G bit distinguishes unicast from multicast, and the U/L bit distinguishes a universal (vendor-assigned) address from a locally administered one. The first three octets form the OUI prefix that identifies the vendor. Everything runs in your browser; no data is sent anywhere.