# llmnrd - Link-Local Multicast Resolution Daemon

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llmnrd is a daemon implementing the Link-Local Multicast Name Resolution (LLMNR)
protocol according to [RFC 4795](https://tools.ietf.org/html/rfc4795). It
currently only supports Linux, as it uses the
[netlink kernel interface](http://man7.org/linux/man-pages/man7/netlink.7.html).

llmnrd will respond to name resolution queries sent by Windows clients in
networks where no DNS server is available. It supports both IPv4 and IPv6.

Installation
============

To build and install llmnrd use the following commands:

```
$ make
$ sudo make install
```

By default, the llmnrd binary will be installed to /usr/local/sbin. To install
the binary to a different installation path, use:

```
$ make
$ sudo make prefix=<path> install
```

Cross-Compilation
=================

To cross-compile llmnrd for a different architecture, use the `CROSS_COMPILE`
make variable. To e.g. build it using the arm-linux-gnueabihf toolchain use:

```
$ make CROSS_COMPILE=arm-linux-gnueabihf-
```

When cross-compiling, you usually don't want to install the generated binary to
your root filesystem, but to the sysroot of a cross-compiled system. Use the
`DESTDIR` variable to change the installation destination path, e.g.

```
$ make DESTDIR=$HOME/sysroot/ prefix=/usr install
```

Usage
=====

To run llmnrd in the default mode (listening on UDP port 5355):

```
$ llmnrd
```

By default, LLMNR name resolution is only possible over IPv4. To additionally
enable LLMNR name resolution over IPv6 use:

```
$ llmnrd -6
```

Use `llmnrd --help` to show additional usage information.

Additionally, the `llmnr-query` utility is shipped together with llmnrd and
can be used to send customized LLMNR queries:

```
$ llmnr-query <hostname>
```

Use `llmnr-query --help` to show additional usage information.

License
=======

llmnrd is free software: you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation, version 2 of the License.

llmnrd is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.  See the GNU General Public License for more details.

Please see the [COPYING](https://github.com/tklauser/llmnrd/blob/master/COPYING)
file for the full license text.

Contributors
============

llmnrd is authored and maintained by Tobias Klauser <tklauser@distanz.ch>

The following people contributed patches and ideas, found and reported bugs or
otherwise helped in the development of llmnrd:

* Elazar Leibovich (@elazarl)
* Martin Hauke
* Michael Evertz (@dvl-mevertz)
* Pali Rohár
* Schimmelreiter (@Schimmelreiter)
* SviMik (@svimik)

Thanks a lot!

References
==========

* [RFC 4795](https://tools.ietf.org/html/rfc4795)
* [Microsoft TechNet article about LLMNR](https://technet.microsoft.com/en-us/library/bb878128.aspx)
* [xllmnrd: An IPv6-only LLMNR responder daemon](http://www.vx68k.org/xllmnrd) ([Repository](https://bitbucket.org/kazssym/xllmnrd/))
07a33fbf1c2e0a88ffc9fc0e465c2a59fd'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Thomas Gleixner &lt;tglx@linutronix.de&gt;</td><td class='right'>2016-06-03 15:05:51 +0200</td></tr>
<tr><th>committer</th><td>Thomas Gleixner &lt;tglx@linutronix.de&gt;</td><td class='right'>2016-06-03 15:05:51 +0200</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/Makefile?h=packet-loop-back&amp;id=2eec3707a33fbf1c2e0a88ffc9fc0e465c2a59fd'>2eec3707a33fbf1c2e0a88ffc9fc0e465c2a59fd</a> (<a href='/cgit.cgi/linux/net-next.git/patch/Makefile?id=2eec3707a33fbf1c2e0a88ffc9fc0e465c2a59fd'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=packet-loop-back&amp;id=2eec3707a33fbf1c2e0a88ffc9fc0e465c2a59fd'>9e47763ecd38f0ddd29f07e1ce199680304449fa</a> /<a href='/cgit.cgi/linux/net-next.git/tree/Makefile?h=packet-loop-back&amp;id=2eec3707a33fbf1c2e0a88ffc9fc0e465c2a59fd'>Makefile</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/Makefile?h=packet-loop-back&amp;id=59fa5860204ffc95128d60cba9f54f9740a42c7d'>59fa5860204ffc95128d60cba9f54f9740a42c7d</a> (<a href='/cgit.cgi/linux/net-next.git/diff/Makefile?h=packet-loop-back&amp;id=2eec3707a33fbf1c2e0a88ffc9fc0e465c2a59fd&amp;id2=59fa5860204ffc95128d60cba9f54f9740a42c7d'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/Makefile?h=packet-loop-back&amp;id=0de6b9979e2e10c79e5702d2d902cd7284d17689'>0de6b9979e2e10c79e5702d2d902cd7284d17689</a> (<a href='/cgit.cgi/linux/net-next.git/diff/Makefile?h=packet-loop-back&amp;id=2eec3707a33fbf1c2e0a88ffc9fc0e465c2a59fd&amp;id2=0de6b9979e2e10c79e5702d2d902cd7284d17689'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge tag 'irqchip-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent</div><div class='commit-msg'>Merge irqchip updates from Marc Zyngier:

- A number of embarassing buglets (GICv3, PIC32)
- A more substential errata workaround for Cavium's GICv3 ITS
  (kept for post-rc1 due to its dependency on NUMA)
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=packet-loop-back&amp;id=2eec3707a33fbf1c2e0a88ffc9fc0e465c2a59fd'>Diffstat</a> (limited to 'Makefile')</div><table summary='diffstat' class='diffstat'>