How do I convert a Cisco MAC to Linux format?

Remove the two dots and insert colons between each pair of hex digits: 0011.2233.4455 becomes 00:11:22:33:44:55.

What does the locally-administered bit mean?

Bit 1 of the first octet. When set, the address was assigned by software rather than burned in by the manufacturer — virtual machines and containers almost always set it.

How is a link-local IPv6 address built from a MAC?

Insert FFFE in the middle of the 48-bit address, flip the universal/local bit, and prepend fe80::. 00:11:22:33:44:55 becomes fe80::211:22ff:fe33:4455.

MAC Address Format Converter

Paste a MAC in any notation and get every convention back at once — Cisco, Linux, Windows, bare hex — plus the multicast and locally-administered bits and the EUI-64 / IPv6 link-local form.

Input

Mode

MAC address

Any separator, any case: dots, colons, hyphens, spaces or nothing at all.

Uppercase outputSome vendors print uppercase; both are accepted on input.

Format conversions

48-bit

Cisco (IOS, NX-OS): 0011.2233.4455
Linux / Unix: 00:11:22:33:44:55
Windows: 00-11-22-33-44-55
Bare hex: 001122334455
Space separated: 00 11 22 33 44 55
OUI (first 24 bits): 001122

Address bits

Unicast / group: Unicast
Assignment: Globally unique (OUI)
Vendor (OUI table): Not in the OUI table

IPv6 interface identifier

RFC 4291 EUI-64 derivation

EUI-64 (colon): 02:11:22:ff:fe:33:44:55
EUI-64 (hyphen): 02-11-22-ff-fe-33-44-55
Link-local address: fe80::211:22ff:fe33:4455

The universal/local bit is flipped, so 00:11:22:33:44:55 becomes 0211:22ff:fe33:4455 as the interface identifier.

Frequently asked

How do I convert a Cisco MAC to Linux format?: Remove the two dots and insert colons between each pair of hex digits: 0011.2233.4455 becomes 00:11:22:33:44:55.
What does the locally-administered bit mean?: Bit 1 of the first octet. When set, the address was assigned by software rather than burned in by the manufacturer — virtual machines and containers almost always set it.
How is a link-local IPv6 address built from a MAC?: Insert FFFE in the middle of the 48-bit address, flip the universal/local bit, and prepend fe80::. 00:11:22:33:44:55 becomes fe80::211:22ff:fe33:4455.

Frequently asked

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