mDNS

(Multicast DNS) Using IP multicast with DNS to provide the capabilities of a DNS server for service discovery in a small network that does not have a DNS server. IP packets are sent to every node on the network with the reserved mDNS multicast address of 224.0.0.251. Devices respond with their service capabilities. mDNS evolved from the IETF's work on zero configuration networking (Zeroconf). See Zeroconf and IP multicast.