MAC Addresses and IP Addresses, What They Reveal

A MAC address identifies a specific physical network interface, assigned by its manufacturer and normally fixed for the device's lifetime. An IP address identifies where a device currently sits on a network, and changes depending on which network it connects to. A laptop keeps the same MAC address at home and at a coffee shop, while its IP address is different at each.

The first three bytes of a MAC address, called the OUI, are assigned by the IEEE to a specific manufacturer, so looking one up can identify what kind of hardware a device is (an Apple product, a Raspberry Pi, a specific router brand) without knowing anything else about it. This is genuinely useful for making sense of an unfamiliar device on a router's connected-devices list.

Because a fixed MAC address could be used to track a device across different networks over time, modern phones and laptops increasingly randomize their MAC address by default, especially while scanning for networks before connecting to one. A randomized address has no real manufacturer behind its prefix, so a vendor lookup against one will simply come back empty, which is expected rather than a fault in the lookup.

Your public IP address is whatever your internet connection, or VPN if you are using one, presents to the outside world. It typically reveals an approximate location and your internet provider or hosting company, but not your exact address or identity on its own. It changes if you switch networks, restart certain routers, or connect through a VPN, which is exactly why checking it is a quick way to confirm a VPN is actually active.

MAC Address Vendor Lookup matches the first three bytes of a MAC address against a list of known manufacturers, and What Is My IP shows your own public address along with its approximate network operator and location. For looking up details about someone else's IP address specifically, IP Lookup covers ASN, hosting provider and location the same way.