Apple Bonjour and Linux zero-configuration networking implementations (e.g., Avahi) use mDNS to discover network peripherals within the local network.
Default port: 5353/UDP
PORT STATE SERVICE
5353/udp open zeroconf
Enumeration
nmap-Pn-sUC-p5353192.168.1.2StartingNmap6.46 (http://nmap.org) at 2015-01-01 10:30 GMTNmapscanreportfor192.168.1.2PORTSTATESERVICE5353/udpopenzeroconf|dns-service-discovery:|9/tcpworkstation| Address=192.168.1.2|22/tcpssh| Address=192.168.1.2|22/tcpsftp-ssh| Address=192.168.1.2|445/tcpsmb| Address=192.168.1.2