.\" -*- tab-width: 4 -*-
.\" 
.\" Copyright (c) 2004 Apple Computer, Inc. All Rights Reserved.
.\" 
.\" Licensed under the Apache License, Version 2.0 (the "License");
.\" you may not use this file except in compliance with the License.
.\" You may obtain a copy of the License at
.\" 
.\"     http://www.apache.org/licenses/LICENSE-2.0
.\" 
.\" Unless required by applicable law or agreed to in writing, software
.\" distributed under the License is distributed on an "AS IS" BASIS,
.\" WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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.\" limitations under the License.
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.\" $Log: dnsextd.8,v $
.\" Revision 1.2  2006/08/14 23:24:56  cheshire
.\" Re-licensed mDNSResponder daemon source code under Apache License, Version 2.0
.\"
.\" Revision 1.1  2004/08/15 18:49:18  cheshire
.\" <rdar://problem/3763030> No man page for dnsextd
.\"
.\"
.\"
.Dd August 2004             \" Date
.Dt dnsextd 8               \" Document Title
.Os Darwin                  \" Operating System
.\"
.Sh NAME
.Nm dnsextd
.Nd BIND Extension Daemon   \" Name Description for whatis database
.\" 
.Sh SYNOPSIS
.Nm
.\"
.Sh DESCRIPTION
.Nm
is a daemon invoked at boot time, running alongside BIND 9,
to implement two EDNS0 extensions to the standard DNS protocol.
.Pp
.Nm
allows clients to perform DNS Updates with an attached lease lifetime,
so that if the client crashes or is disconnected from the network, its
address records will be automatically deleted after the lease expires.
.Pp
.Nm
allows clients to perform long-lived queries. Instead of rapidly polling
the server to discover when information changes, long-lived queries
enable a client to indicate its interest in some set of data, and then
be notified asynchronously by the server whenever any of that data changes.
.Pp
.Nm
has no user-specifiable command-line argument, and users should not run
.Nm
manually.
.\"
.Sh SEE ALSO
.Xr mDNS 1
.Xr mDNSResponder 8
.Pp
For information on Dynamic DNS Update, see RFC 2136
"Dynamic Updates in the Domain Name System (DNS UPDATE)"
.Pp
For information on Dynamic DNS Update Leases, see
.Pa http://files.dns-sd.org/draft-dns-update-leases.txt
.Pp
For information on Long-Lived Queries, see
.Pa http://files.dns-sd.org/draft-dns-llq.txt
.\"
.Sh BUGS
.Nm
bugs are tracked in Apple Radar component "mDNSResponder".
.\"
.Sh HISTORY
The
.Nm
daemon first appeared in Mac OS X 10.4 (Tiger).