macOS / binaries /

mDNSResponder

/usr/sbin/mDNSResponder
Multicast and unicast DNS daemon

Daemon invoked at boot time to implement Multicast DNS and DNS Service Discovery. mDNSResponder listens on UDP port 5353 for Multicast DNS Query packets. When it receives a query for which it knows an answer, mDNSResponder issues the appropriate Multicast DNS Reply packet. mDNSResponder also performs Unicast and Multicast DNS Queries on behalf of client processes, and maintains a cache of the replies.

source: man