Multicast DNS (mDNS) is a zero-configuration protocol that lets you perform DNS-like operations on the local network in the absence of a conventional, unicast DNS server. The protocol uses the same API, packet formats, and operating semantics as DNS, allowing you to resolve domain names on the local network. DNS Service Discovery (DNS-SD) is a protocol that allows clients to discover a list of named instances of services (such as test._ipps._tcp.local, or linux._ssh._tcp.local) in a domain using standard DNS queries. DNS-SD is most often used in conjunction with mDNS but isn’t dependent on it. They’re both used by many IoT devices, such as network printers, Apple TVs, Google Chromecast, Network-Attached Storage (NAS) devices, and cameras.
Default port: 5353/UDP