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Network Protocols Glossary

What is a network protocol? Protocols are the rules of the road for how data exists and moves on the network. They allow many different systems and computers to communicate.

Link-Local Multicast Name Resolution (LLMNR) Protocol

What is Link-Local Multicast Name Resolution (LLMNR) Protocol?

LLMNR is a protocol designed to allow devices on a local network to resolve hostnames without relying on a DNS server. It operates at the link layer (Layer 2) of the OSI model, hence the name. LLMNR was initially intended as a fallback mechanism when DNS is unavailable. However, it's important to note that due to its security vulnerabilities, it's generally recommended to disable LLMNR.


What is the purpose of LLMNR Protocol

When a device needs to resolve a hostname, it broadcasts an LLMNR query to all devices on the local network. If a device with the requested hostname is on the same network, it responds to the query with its IP address. The querying device receives the IP address and can then communicate with the target host by its IP address.