Robert Greenwalt | 47e4ceb | 2012-03-26 15:36:57 -0700 | [diff] [blame] | 1 | .\" -*- tab-width: 4 -*- |
| 2 | .\" |
| 3 | .\" Copyright (c) 2003-2004 Apple Computer, Inc. All Rights Reserved. |
| 4 | .\" |
| 5 | .\" Licensed under the Apache License, Version 2.0 (the "License"); |
| 6 | .\" you may not use this file except in compliance with the License. |
| 7 | .\" You may obtain a copy of the License at |
| 8 | .\" |
| 9 | .\" http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | .\" |
| 11 | .\" Unless required by applicable law or agreed to in writing, software |
| 12 | .\" distributed under the License is distributed on an "AS IS" BASIS, |
| 13 | .\" WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | .\" See the License for the specific language governing permissions and |
| 15 | .\" limitations under the License. |
| 16 | .\" |
| 17 | .Dd April 2004 \" Date |
| 18 | .Dt mDNSResponder 8 \" Document Title |
| 19 | .Os Darwin \" Operating System |
| 20 | .\" |
| 21 | .Sh NAME |
| 22 | .Nm mDNSResponder |
| 23 | .Nd Multicast and Unicast DNS daemon \" Name Description for whatis database |
| 24 | .\" |
| 25 | .Sh SYNOPSIS |
| 26 | .Nm |
| 27 | .\" |
| 28 | .Sh DESCRIPTION |
| 29 | .Nm |
| 30 | (also known as |
| 31 | .Nm mdnsd |
| 32 | on some systems) |
| 33 | is a daemon invoked at boot time to implement Multicast DNS and DNS Service Discovery. On |
| 34 | Mac OS X 10.6 (Snow Leopard), |
| 35 | .Nm |
| 36 | is also the system-wide Unicast DNS Resolver. |
| 37 | .Pp |
| 38 | .Nm |
| 39 | listens on UDP port 5353 for Multicast DNS Query packets. |
| 40 | When it receives a query for which it knows an answer, |
| 41 | .Nm |
| 42 | issues the appropriate Multicast DNS Reply packet. |
| 43 | .Pp |
| 44 | .Nm |
| 45 | also performs Unicast and Multicast DNS Queries on behalf of client processes, and |
| 46 | maintains a cache of the replies. |
| 47 | .Pp |
| 48 | .Nm |
| 49 | has no user-specifiable command-line argument, and users should not run |
| 50 | .Nm |
| 51 | manually. |
| 52 | .Pp |
| 53 | .Ss LOGGING |
| 54 | There are several methods with which to examine |
| 55 | .Nm Ns 's internal state for debugging and diagnostic purposes. The syslog(1) |
| 56 | logging levels map as follows: |
| 57 | .Pp |
| 58 | .Dl Error - Error messages |
| 59 | .Dl Warning - Client-initiated operations |
| 60 | .Dl Notice - Sleep proxy operations |
| 61 | .Dl Info - Informational messages |
| 62 | .Pp |
| 63 | By default, only log level Error is logged. |
| 64 | .Pp |
| 65 | A SIGUSR1 signal toggles additional logging, with Warning and Notice |
| 66 | enabled by default: |
| 67 | .Pp |
| 68 | .Dl % sudo killall -USR1 mDNSResponder |
| 69 | .Pp |
| 70 | Once this logging is enabled, users can additionally use syslog(1) |
| 71 | to change the log filter for the process. For example, to enable log levels Emergency - Debug: |
| 72 | .Pp |
| 73 | .Dl % sudo syslog -c mDNSResponder -d |
| 74 | .Pp |
| 75 | A SIGUSR2 signal toggles packet logging: |
| 76 | .Pp |
| 77 | .Dl % sudo killall -USR2 mDNSResponder |
| 78 | .Pp |
| 79 | A SIGINFO signal will dump a snapshot summary of the internal state to |
| 80 | .Pa /var/log/system.log Ns : |
| 81 | .Pp |
| 82 | .Dl % sudo killall -INFO mDNSResponder |
| 83 | .Sh FILES |
| 84 | .Pa /usr/sbin/mDNSResponder \" Pathname |
| 85 | .\" |
| 86 | .Sh SEE ALSO |
| 87 | .Xr mDNS 1 |
| 88 | .Pp |
| 89 | For information on Multicast DNS, see |
| 90 | .Pa http://www.multicastdns.org/ |
| 91 | .Pp |
| 92 | For information on DNS Service Discovery, see |
| 93 | .Pa http://www.dns-sd.org/ |
| 94 | .Pp |
| 95 | For information on how to use the Multicast DNS and the |
| 96 | DNS Service Discovery APIs on Mac OS X and other platforms, see |
| 97 | .Pa http://developer.apple.com/bonjour/ |
| 98 | .Pp |
| 99 | For the source code to |
| 100 | .Nm , see |
| 101 | .Pa http://developer.apple.com/darwin/projects/bonjour/ |
| 102 | .\" |
| 103 | .Sh BUGS |
| 104 | .Nm |
| 105 | bugs are tracked in Apple Radar component "mDNSResponder". |
| 106 | .\" |
| 107 | .Sh HISTORY |
| 108 | The |
| 109 | .Nm |
| 110 | daemon first appeared in Mac OS X 10.2 (Jaguar). |
| 111 | .Pp |
| 112 | Also available from the Darwin open source repository |
| 113 | (though not officially supported by Apple) are |
| 114 | .Nm |
| 115 | daemons for other platforms, including Mac OS 9, Microsoft Windows, |
| 116 | Linux, FreeBSD, NetBSD, Solaris, and other POSIX systems. |