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mdnsresponder(8) [osx man page]

mDNSResponder(8)					    BSD System Manager's Manual 					  mDNSResponder(8)

NAME

     mDNSResponder -- Multicast and Unicast DNS daemon

SYNOPSIS

     mDNSResponder

DESCRIPTION

     mDNSResponder (also known as mdnsd on some systems) is a daemon invoked at boot time to implement Multicast DNS and DNS Service Discovery. On
     Mac OS X 10.6 (Snow Leopard), mDNSResponder is also the system-wide Unicast DNS Resolver.

     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.

     mDNSResponder has no user-specifiable command-line argument, and users should not run mDNSResponder manually.

LOGGING

     There are several methods with which to examine mDNSResponder's internal state for debugging and diagnostic purposes. The syslog(1) logging
     levels map as follows:

	   Error - Error messages
	   Warning - Client-initiated operations
	   Notice - Sleep proxy operations
	   Info - Informational messages

     By default, only log level Error is logged.

     A SIGUSR1 signal toggles additional logging, with Warning and Notice enabled by default:

	   % sudo killall -USR1 mDNSResponder

     Once this logging is enabled, users can additionally use syslog(1) to change the log filter for the process. For example, to enable log lev-
     els Emergency - Debug:

	   % sudo syslog -c mDNSResponder -d

     A SIGUSR2 signal toggles packet logging:

	   % sudo killall -USR2 mDNSResponder

     A SIGINFO signal will dump a snapshot summary of the internal state to /var/log/system.log:

	   % sudo killall -INFO mDNSResponder

FILES

     /usr/sbin/mDNSResponder

INFO

     For information on Multicast DNS, see http://www.multicastdns.org/

     For information on DNS Service Discovery, see http://www.dns-sd.org/

     For information on how to use the Multicast DNS and the DNS Service Discovery APIs on Mac OS X and other platforms, see
     http://developer.apple.com/bonjour/

     For the source code to mDNSResponder, see http://developer.apple.com/darwin/projects/bonjour/

BUGS

     mDNSResponder bugs are tracked in Apple Radar component "mDNSResponder".

HISTORY

     The mDNSResponder daemon first appeared in Mac OS X 10.2 (Jaguar).

     Also available from the Darwin open source repository (though not officially supported by Apple) are mDNSResponder daemons for other plat-
     forms, including Mac OS 9, Microsoft Windows, Linux, FreeBSD, NetBSD, Solaris, and other POSIX systems.

Darwin								   June 1, 2019 							    Darwin

Check Out this Related Man Page

networkd(8)						    BSD System Manager's Manual 					       networkd(8)

NAME

     networkd -- network daemon.

SYNOPSIS

     networkd

DESCRIPTION

     networkd is a launch-on-demand daemon that performs opreations on behalf of code in libystem_network, a component of libSystem.

     networkd has no user-specifiable command-line argument, and users should not run networkd manually.

   LOGGING
     There are several methods with which to examine networkd's internal state for debugging and diagnostic purposes. The syslog(1) logging levels
     map as follows:

	   Error - Error messages
	   Warning - Non-fatal concerns
	   Notice - Internal state messages
	   Info - Informational messages

     By default, only log level Notice through Error is logged.

     Syslog may be used to modify the mask which logging levels are logged.  For example, to enable log levels Emergency - Debug :

	   % sudo syslog -c networkd -d

     The networkd settings file may also be used to change the log level.  This method will add some additional logging that may be missing using
     the syslog technique listed above. This method is also persistent across runs of networkd For example, to enable log levels Emergency (1)
     through Debug (7):

	   % sudo defaults write /Library/Preferences/com.apple.networkd networkd_log_level -int 7

     The networkd settings file may also be used to change the log level for code in libsystem_network. For example, to enable log levels Emer-
     gency (1) through Debug (7) for libsystem_network code:

	   % sudo defaults write /Library/Preferences/com.apple.networkd libnetcore_log_level -int 7

     A SIGINFO signal will dump a snapshot summary of the internal state to the system log at log level NOTICE :

	   % sudo killall -INFO networkd

FILES

     /usr/libexec/networkd
	 The binary.

     /System/Library/LaunchDaemons/com.apple.networkd.plist
	 The launchd.plist(5) controlling the networkd job.

     /Library/Preferences/com.apple.networkd.plist
	 An optional preferences file read by networkd.

BUGS

     networkd bugs are tracked in Apple Radar component "networkd".

HISTORY

     networkd first appeared in Mac OS X 10.7.

SEE ALSO

     networkd_privileged(8), syslogd(8), launchd.plist(5)

Darwin								   June 2, 2019 							    Darwin
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