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.
[1] It is also implemented by systemd-resolved on Linux.
[2] LLMNR is defined in RFC 4795 but was not adopted as an IETF standard.
[3] As of April 2022, Microsoft has begun the process of phasing out both LLMNR and NetBIOS name resolution in favour of mDNS.
[4] 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.