AKA as mdnsd , a daemon invoked at boot time to implement Multicast DNS and DNS Service Discovery, the system-wide Unicast DNS Resolver.
To flush DNS cache: sudo killall -HUP mDNSResponder
Apple's "Zero Configuration Networking" application,
Listens on UDP port 5353 for Multicast DNS Query packets. When it receives a query for which it knows an answer, it issues the appropriate Multicast DNS Reply packet.
Performs Unicast and Multicast DNS Queries on behalf of client processes, and maintains a cache of the replies.
not run mDNSResponder manually.
SIGUSR1
toggles additional logging, with Warning
and Notice
enabled by default:
% sudo killall -USR1 mDNSResponder
Once this logging is enabled, syslog(1) to change the log filter.
For example, to enable ALL log levels :
% sudo syslog -c mDNSResponder -d
SIGUSR2
toggles packet logging:
% sudo killall -USR2 mDNSResponder
SIGINFO
dumps a snapshot summary of the internal state to /var/log/system.log:
% sudo killall -INFO mDNSResponder
DeregisterInterface: Frequent transitions for interface en1i …
sudo launchctl unload /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist
sudo launchctl load /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist
( -w (disable) is deprecated)