MAC Address Formatter
Convert MAC addresses between colon, hyphen, Cisco dot notation, and raw formats. Click any format to copy.
MAC Address Format Reference
A MAC (Media Access Control) address is a 48-bit hardware identifier assigned to every network interface card (NIC). It is burned into the hardware by the manufacturer and is theoretically globally unique. MAC addresses operate at Layer 2 (Data Link layer) of the OSI model and are used for local network communication within a broadcast domain.
The same 48-bit MAC address is written differently depending on the operating system or vendor, which causes constant conversion headaches for network engineers working across different platforms and equipment vendors.
How to Use This Tool
- Enter a MAC address in any format in the input field.
- Click Format (or press Enter).
- All output formats appear simultaneously — click any one to copy it.
MAC Address Formats by Platform
- Linux / macOS —
aa:bb:cc:dd:ee:ff(lowercase colon, shown inip linkandifconfig) - Windows —
AA-BB-CC-DD-EE-FF(uppercase hyphen, shown inipconfig /all) - Cisco IOS —
aabb.ccdd.eeff(lowercase dot notation, shown inshow mac address-table) - Raw / No separator —
AABBCCDDEEFF(used in databases, some APIs, and RADIUS servers)
Understanding the MAC Address Structure
- OUI (bytes 1–3) — Organizationally Unique Identifier. Assigned by IEEE to manufacturers. Identifies the vendor (e.g.,
00:50:56= VMware). - NIC-specific (bytes 4–6) — Assigned by the manufacturer to uniquely identify each device.
- Bit 1 of byte 1 — If set (1), the MAC is a multicast address. Multicast MACs range from
01:00:00:00:00:00toFF:FF:FF:FF:FF:FF. - Bit 2 of byte 1 — If set (1), the MAC is locally administered (not assigned by IEEE). Common in VMs, Docker containers, and devices with MAC randomization.
Frequently Asked Questions
Yes. MAC addresses can be changed in software — this is called MAC spoofing. On Linux:
ip link set dev eth0 address AA:BB:CC:DD:EE:FF. On macOS and Windows, you can change it via Network Adapter settings. The hardware-burned MAC (called the BIA, Burned-In Address) is permanent, but the active MAC can be overridden. Modern phones randomize their MAC for Wi-Fi scanning to protect privacy.In theory yes, but in practice no. The IEEE assigns OUI prefixes to manufacturers who should ensure their devices have unique MACs, but counterfeiting and manufacturing errors occur. More importantly, MAC addresses are only locally significant — they don't route over the internet. Two devices with the same MAC on different networks causes no conflict, but two devices with the same MAC on the same Layer 2 segment will cause communication failures.
FF:FF:FF:FF:FF:FF is the Layer 2 broadcast address. Frames sent to this address are delivered to every device on the local network segment. ARP requests use broadcast to ask "who has IP x.x.x.x?" before learning the target's MAC address.Hypervisors (VMware, VirtualBox, Hyper-V) generate virtual MAC addresses for VMs. VMware uses OUI prefix
00:50:56, VirtualBox uses 08:00:27, and QEMU/KVM uses 52:54:00. These are locally administered MACs assigned by the hypervisor, not IEEE-registered hardware MACs.MAC addresses operate at Layer 2 and identify hardware within a local network. They don't route across networks — a router replaces source and destination MACs at each hop. IP addresses operate at Layer 3 and provide global routing. ARP (Address Resolution Protocol) maps IP addresses to MAC addresses within a local subnet. Think of it this way: IP addresses are like postal addresses (for routing), MAC addresses are like names on a door (for local delivery).