The Link-Local Multicast Name Resolution (LLMNR) is a protocol based on the Domain Name System (DNS) packet format that allows both IPv4 and IPv6 hosts to perform name resolution for hosts on the same local link.

It is included in Windows Vista, Windows Server 2008, Windows 7, Windows 8, Windows 10. It is also implemented by systemd-resolved on Linux.

In responding to queries, responders listen on port 5355/UDP on the following link-scope multicast address:

IPv4 -> 224.0.0.252, MAC address 01-00-5E-00-00-FC

IPv6 -> FF02:0:0:0:0:0:1:3 (this notation can be abbreviated as FF02::1:3), MAC address 33-33-00-01-00-03

The responders also listen on port 5355/TCP on the unicast address that the host uses to respond to queries.