Hardware Identity
MAC / OUI Tool
Inspect a MAC address — vendor lookup, address-type classification (unicast / multicast, globally unique / locally administered), and detection of well-known multicast and virtual-router patterns. EUI-64 tab converts between 48-bit MAC and IPv6 link-local interface ID.
aa:bb:cc:dd:ee:ff, aa-bb-cc-dd-ee-ff, aabb.ccdd.eeff, or aabbccddeeff.fe80:: link-local. Or enter an IPv6 address with FFFE in the middle of the host portion to recover the original MAC.Well-known MAC Patterns
Multicast and virtual-router MACs you'll see on a typical enterprise segment.
| Pattern | Name | Description |
|---|---|---|
| FF:FF:FF:FF:FF:FF | Broadcast | Layer-2 broadcast (all hosts) |
| 01:00:5E:0x:xx:xx | IPv4 Multicast | RFC 1112 — last 23 bits derived from IPv4 group address |
| 33:33:xx:xx:xx:xx | IPv6 Multicast | RFC 2464 — last 32 bits = lower 32 of IPv6 group |
| 01:80:C2:00:00:00 | STP / 802.1D | Spanning Tree BPDUs |
| 01:80:C2:00:00:0E | LLDP | Link Layer Discovery (IEEE 802.1AB) |
| 01:80:C2:00:00:03 | LACP / 802.1X | Slow Protocols, EAPOL |
| 01:00:0C:CC:CC:CC | Cisco CDP / VTP / DTP | Cisco discovery and trunking protocols |
| 00:00:5E:00:01:VV | VRRPv2 IPv4 | RFC 5798 — last byte = VRID (1–255) |
| 00:00:5E:00:02:VV | VRRPv3 IPv6 | last byte = VRID |
| 00:00:0C:07:AC:GG | HSRPv1 | Cisco — last byte = HSRP group |
| 00:00:0C:9F:Fx:xx | HSRPv2 IPv4 | last 12 bits = HSRP group (0–4095) |
| 01:00:5E:00:00:05/06 | OSPF AllSPF / AllD | OSPFv2/v3 routing multicast |
| 01:00:5E:00:00:09 | RIPv2 | 224.0.0.9 |
| 01:00:5E:00:00:0A | EIGRP | 224.0.0.10 |
| 33:33:00:00:00:01 | IPv6 all-nodes | ff02::1 |
| 33:33:00:00:00:02 | IPv6 all-routers | ff02::2 |
Vendor Coverage
This tool ships the full IEEE OUI registry — 55,950 entries across MA-L (24-bit /24 OUI), MA-M (28-bit), MA-S (36-bit), and IAB sub-block assignments. Loaded on demand from standards-oui.ieee.org; cached in your browser after first lookup. Plus a small fallback for well-known locally-administered prefixes (Docker, QEMU, AWS, etc.) that aren't part of the IEEE registry.
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