Netzwerk
MAC Address Lookup
The MAC address lookup tool identifies the manufacturer or vendor associated with a MAC address by querying the IEEE OUI (Organizationally Unique Identifier) database. Enter a full MAC address or just the first three octets (OUI) to find out which company registered that prefix. This is useful for network inventory, security investigations, and identifying unknown devices on a network.
What is MAC Address Lookup?
Every network interface manufacturer registers one or more 24-bit OUI prefixes with the IEEE. The OUI forms the first three octets of all MAC addresses produced by that manufacturer, making it possible to identify who made a network device from its MAC address alone. The MAC lookup tool queries an offline or API-backed copy of the IEEE OUI database and returns the registered company name, address, and any additional details available for a given prefix.
How does it work?
Enter a full MAC address (e.g., 00:1A:2B:3C:4D:5E) or just the OUI portion (e.g., 00:1A:2B). The tool extracts the first three octets, normalizes the format, and looks up the OUI in the IEEE registry. The result includes the vendor name and registration details. The lookup is performed against a regularly updated database derived from the official IEEE MA-L (MAC Address Large), MA-M, and MA-S registries.
Typical Use Cases
- Identifying unknown devices on a network by their MAC address
- Investigating a suspicious device seen in ARP tables or network scans
- Verifying whether a MAC address belongs to a known hardware vendor
- Network inventory management: associating devices with their manufacturers
Step-by-step Guide
- Step 1: Enter a full MAC address or the first three octets (OUI) into the input field.
- Step 2: Click Lookup to query the IEEE OUI database.
- Step 3: Read the returned vendor name and registration details.
- Step 4: Use the vendor information to identify or categorize the device.
Example
Input
00:1A:2B:3C:4D:5E
Output
OUI: 00:1A:2B — Vendor: Cisco Systems, Inc.
Tips & Notes
- MAC addresses can be spoofed — a device may report a MAC address that does not match its actual hardware.
- Locally administered addresses (second bit of first byte = 1) are not OUI-registered and will return no vendor.
- Virtualization platforms (VMware, VirtualBox, Hyper-V) use their own registered OUI ranges for virtual NICs.
Frequently Asked Questions
Why does the lookup return no result for some MAC addresses?
Locally administered addresses, multicast addresses, and some older or regional OUI registrations may not appear in the database. Also, manufacturers can use multiple OUI blocks and not all are equally well documented.
Can I look up a MAC address from a Wi-Fi scan?
Yes. Wi-Fi clients broadcast their MAC address in probe requests. Note that modern smartphones use MAC address randomization for privacy, so the OUI of a randomized address (bit 1 set) will not identify the device manufacturer.
MAC Address Lookup
Identify the manufacturer and device information from a MAC address — with OUI lookup, address properties, and EUI-64 representation.
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