MAC Address Lookup & Formatter
Convert a MAC address between colon, hyphen, Cisco and plain formats, identify the vendor from its OUI, check the unicast and local bits, and build the matching IPv6 link-local address.
Accepts AA:BB:CC:DD:EE:FF, AA-BB-CC-DD-EE-FF, AABB.CCDD.EEFF and AABBCCDDEEFF.
AA:BB:CC:DD:EE:FF
3C:5A:37:12:34:56
OUI
3C5A37
NIC
123456
Address type
Unicast device
Assignment
Globally unique (OUI)
Vendor
Samsung
Matched OUI 3C5A37 in the offline subset.
IPv6 link-local (EUI-64)
fe80::3e5a:37ff:fe12:3456
EUI-64 inserts FF:FE and flips the local bit. Privacy extensions may use a random value instead.
- OUI 3C5A37 is registered to Samsung.
Generate a random MAC
Useful for test fixtures and virtual lab setup. Do not use a random address to impersonate hardware you do not own.
Reading the first byte
- Bit 0 (I/G): 0 means unicast to one interface; 1 means multicast to a group.
- Bit 1 (U/L): 0 means the OUI is globally assigned; 1 means the address was set locally.
- Only the first three bytes belong to the vendor. The last three are assigned by that vendor.
- MAC addresses are flat, local-network identifiers. They are not routable across the internet.
Need to plan a subnet? Use the Subnet / CIDR Calculator, convert addresses with the IP Address Converter, or expand an IPv6 address with the IPv6 Tools.
Frequently asked questions
What does a MAC address tell you?
The first three bytes are the OUI, which the IEEE assigns to a manufacturer. The last three identify the interface. Two bits in the first byte describe the address type and assignment.
Can a MAC address be changed?
Yes. Operating systems and virtual machines can set a locally administered MAC address. A MAC address alone is therefore not a reliable device identity or security control.
How accurate is the vendor match?
The tool ships a curated offline subset of common OUIs, not the full IEEE registry. A prefix may be missing or reassigned. Treat a match as a hint and confirm critical results with the IEEE registry.
Where does the IPv6 address come from?
EUI-64 inserts FF:FE in the middle of the MAC and flips the locally administered bit, then prefixes the result with fe80::. Modern privacy extensions often use a random identifier.
Related tools
Related tools
More from Networking
Build custom software with us
From internal tools to full platforms — we deliver end to end.