Link-Local Multicast Name Resolution


The Link-Local Multicast Name Resolution is a protocol based on the Domain Name System 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 and Windows 10. It is also implemented by systemd-resolved on GNU/Linux. LLMNR is defined in RFC 4795.

Protocol details

In responding to queries, responders listen on UDP port 5355 on the following link-scope Multicast address:
The responders also listen on TCP port 5355 on the unicast address that the host uses to respond to queries.

Packet header structure