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<table class="head">
<tr>
<td class="head-ltitle">MLD(4)</td>
<td class="head-vol">Device Drivers Manual</td>
<td class="head-rtitle">MLD(4)</td>
</tr>
</table>
<div class="manual-text">
<section class="Sh">
<h1 class="Sh" id="NAME"><a class="permalink" href="#NAME">NAME</a></h1>
<p class="Pp"><code class="Nm">mld</code> — <span class="Nd">Multicast
Listener Discovery Protocol</span></p>
</section>
<section class="Sh">
<h1 class="Sh" id="SYNOPSIS"><a class="permalink" href="#SYNOPSIS">SYNOPSIS</a></h1>
<p class="Pp"><code class="In">#include
<<a class="In">sys/types.h</a>></code>
<br/>
<code class="In">#include <<a class="In">sys/socket.h</a>></code>
<br/>
<code class="In">#include <<a class="In">netinet/in.h</a>></code>
<br/>
<code class="In">#include <<a class="In">netinet/in_systm.h</a>></code>
<br/>
<code class="In">#include <<a class="In">netinet/ip6.h</a>></code>
<br/>
<code class="In">#include <<a class="In">netinet/icmp6.h</a>></code>
<br/>
<code class="In">#include <<a class="In">netinet6/mld6.h</a>></code></p>
<p class="Pp"><var class="Ft">int</var>
<br/>
<code class="Fn">socket</code>(<var class="Fa" style="white-space: nowrap;">AF_INET6</var>,
<var class="Fa" style="white-space: nowrap;">SOCK_RAW</var>,
<var class="Fa" style="white-space: nowrap;">IPPROTO_ICMPV6</var>);</p>
</section>
<section class="Sh">
<h1 class="Sh" id="DESCRIPTION"><a class="permalink" href="#DESCRIPTION">DESCRIPTION</a></h1>
<p class="Pp">MLD is a control plane protocol used by IPv6 hosts and routers to
propagate multicast group membership information. Normally this protocol is
not used directly, except by the kernel itself, in response to multicast
membership requests by user applications. Multicast routing protocol daemons
may open a raw socket to directly interact with <code class="Nm">mld</code>
and receive membership reports.</p>
<p class="Pp">As of <span class="Ux">FreeBSD 8.0</span>, MLD version 2 is
implemented. This adds support for Source-Specific Multicast (SSM), whereby
applications may communicate to upstream multicast routers that they are
only interested in receiving multicast streams from particular sources. The
retransmission of state-change reports adds some robustness to the
protocol.</p>
</section>
<section class="Sh">
<h1 class="Sh" id="SYSCTL_VARIABLES"><a class="permalink" href="#SYSCTL_VARIABLES">SYSCTL
VARIABLES</a></h1>
<dl class="Bl-tag">
<dt>net.inet6.mld.ifinfo</dt>
<dd>This opaque read-only variable exposes the per-link MLDv2 status to
<a class="Xr">ifmcstat(8)</a>.</dd>
<dt>net.inet6.mld.gsrdelay</dt>
<dd>This variable specifies the time threshold, in seconds, for processing
Group-and-Source Specific Queries (GSR). As GSR query processing requires
maintaining state on the host, it may cause memory to be allocated, and is
therefore a potential attack point for Denial-of-Service (DoS). If more
than one GSR query is received within this threshold, it will be dropped,
to mitigate the potential for DoS.</dd>
<dt>net.inet6.mld.v1enable</dt>
<dd>If this variable is non-zero, then MLDv1 membership queries (and host
reports) will be processed by this host, and backwards compatibility will
be enabled until the v1 'Older Version Querier Present' timer expires.
This sysctl is normally enabled by default.</dd>
</dl>
</section>
<section class="Sh">
<h1 class="Sh" id="SEE_ALSO"><a class="permalink" href="#SEE_ALSO">SEE
ALSO</a></h1>
<p class="Pp"><a class="Xr">netstat(1)</a>, <a class="Xr">sourcefilter(3)</a>,
<a class="Xr">icmp6(4)</a>, <a class="Xr">inet(4)</a>,
<a class="Xr">multicast(4)</a>, <a class="Xr">ifmcstat(8)</a></p>
</section>
<section class="Sh">
<h1 class="Sh" id="HISTORY"><a class="permalink" href="#HISTORY">HISTORY</a></h1>
<p class="Pp">The <code class="Nm">mld</code> manual page appeared in
<span class="Ux">FreeBSD 8.0</span>.</p>
</section>
</div>
<table class="foot">
<tr>
<td class="foot-date">April 8, 2013</td>
<td class="foot-os">FreeBSD 15.0</td>
</tr>
</table>
|
