NetBEUI (NetBIOS extended user interface) is a network protocol that was commonly used in the early days of personal computing, particularly in small local area networks (LANs). IBM developed it and later adapted it to Microsoft for early network operating systems, such as LAN Manager and Windows for Workgroups. You could only use NetBEUI in a small, local network. Because the protocol doesn’t support routing, it can’t be used to send data over the internet or large networks with multiple segments. Its modern networking limitations made it largely obsolete, with protocols, such as TCP/IP, taking its place.
How does NetBEUI work?
NetBEUI processed communication between computers on a LAN using unique NetBIOS names for each device instead of IP addresses. It relied heavily on broadcast communication to discover other devices and services on the network. For example, a computer would broadcast a message to find another computer by its NetBIOS name.
NetBEUI operated primarily at the OSI model’s session layer (Layer 5) and didn’t have a dedicated network layer (Layer 3) component, which is its main limitation. Since it cannot handle traffic across different network segments or routers, it’s unsuitable for modern networks.