.\" -*- tab-width: 4 -*-
.\" 
.\" Copyright (c) 2003-2004 Apple Computer, Inc. All Rights Reserved.
.\" 
.\" Licensed under the Apache License, Version 2.0 (the "License");
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.\" $Log: mDNSResponder.8,v $
.\" Revision 1.8  2006/10/06 17:31:33  mkrochma
.\" <rdar://problem/4769407> Typo in man page for mDNSResponder(8)
.\"
.\" Revision 1.7  2006/08/14 23:24:56  cheshire
.\" Re-licensed mDNSResponder daemon source code under Apache License, Version 2.0
.\"
.\" Revision 1.6  2005/02/10 22:35:28  cheshire
.\" <rdar://problem/3727944> Update name
.\"
.\" Revision 1.5  2004/06/29 02:41:38  cheshire
.\" Add note that mDNSResponder is called mdnsd on some systems
.\"
.\" Revision 1.4  2004/05/18 18:14:36  cheshire
.\" Minor wording update
.\"
.\" Revision 1.3  2004/04/22 02:56:08  cheshire
.\" <rdar://problem/3619494>: mDNSResponder man page format error
.\"
.\" Revision 1.2  2004/04/12 18:03:24  ksekar
.\" <rdar://problem/3619494>: mDNSResponder man page format error
.\"
.\" Revision 1.1  2003/11/13 03:21:38  cheshire
.\" <rdar://problem/3086886>: No man page for mDNSResponder
.\"
.\"
.\"
.Dd April 2004              \" Date
.Dt mDNSResponder 8         \" Document Title
.Os Darwin                  \" Operating System
.\"
.Sh NAME
.Nm mDNSResponder
.Nd Multicast DNS daemon    \" Name Description for whatis database
.\" 
.Sh SYNOPSIS
.Nm
.\"
.Sh DESCRIPTION
.Nm
(also known as
.Nm mdnsd
on some systems)
is a daemon invoked at boot time to implement Multicast DNS
and DNS Service Discovery.
.Pp
.Nm
listens UDP port 5353 for Multicast DNS Query packets.
When it receives a query for which it knows an answer,
.Nm
issues the appropriate Multicast DNS Reply packet.
.Pp
.Nm
also performs Multicast DNS Queries on behalf of client processes,
and maintains a cache of the replies.
.Pp
.Nm
has no user-specifiable command-line argument, and users should not run
.Nm
manually.
.Pp
To examine
.Nm Ns 's internal state, for debugging and diagnostic purposes,
send it a SIGINFO signal, and it will then dump a snapshot summary
of its internal state to
.Pa /var/log/system.log Ns , e.g.
.Pp
.Dl sudo killall -INFO mDNSResponder
.Sh FILES
.Pa /usr/sbin/mDNSResponder \" Pathname
.\"
.Sh SEE ALSO
.Xr mDNS 1
.Pp
For information on Multicast DNS, see
.Pa http://www.multicastdns.org/
.Pp
For information on DNS Service Discovery, see
.Pa http://www.dns-sd.org/
.Pp
For information on how to use the Multicast DNS and the
DNS Service Discovery APIs on Mac OS X and other platforms, see
.Pa http://developer.apple.com/bonjour/
.Pp
For the source code to
.Nm , see
.Pa http://developer.apple.com/darwin/projects/bonjour/
.\"
.Sh BUGS
.Nm
bugs are tracked in Apple Radar component "mDNSResponder".
.\"
.Sh HISTORY
The
.Nm
daemon first appeared in Mac OS X 10.2 (Jaguar).
.Pp
Also available from the Darwin open source repository
(though not officially supported by Apple) are 
.Nm
daemons for other platforms, including Mac OS 9, Microsoft Windows,
Linux, FreeBSD, NetBSD, Solaris, and other POSIX systems.