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MLD(4)		       FreeBSD Kernel Interfaces Manual			MLD(4)

NAME
     mld -- Multicast Listener Discovery Protocol

SYNOPSIS
     #include <sys/types.h>
     #include <sys/socket.h>
     #include <netinet/in.h>
     #include <netinet/in_systm.h>
     #include <netinet/ip6.h>
     #include <netinet/icmp6.h>
     #include <netinet6/mld6.h>

     int
     socket(AF_INET6, SOCK_RAW,	IPPROTO_ICMPV6);

DESCRIPTION
     MLD is a control plane protocol used by IPv6 hosts	and routers to propa-
     gate 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 mld and receive
     membership	reports.

     As	of FreeBSD 8.0,	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.

SYSCTL VARIABLES
     net.inet6.mld.ifinfo
	     This opaque read-only variable exposes the	per-link MLDv2 status
	     to	ifmcstat(8).

     net.inet6.mld.gsrdelay
	     This variable specifies the time threshold, in seconds, for pro-
	     cessing 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.

     net.inet6.mld.v1enable
	     If	this variable is non-zero, then	MLDv1 membership queries (and
	     host reports) will	be processed by	this host, and backwards com-
	     patibility	will be	enabled	until the v1 'Older Version Querier
	     Present' timer expires.  This sysctl is normally enabled by
	     default.

SEE ALSO
     netstat(1), sourcefilter(3), icmp6(4), inet(4), multicast(4), ifmcstat(8)

HISTORY
     The mld manual page appeared in FreeBSD 8.0.

FreeBSD	10.1			 April 8, 2013			  FreeBSD 10.1

NAME | SYNOPSIS | DESCRIPTION | SYSCTL VARIABLES | SEE ALSO | HISTORY

Want to link to this manual page? Use this URL:
<http://www.freebsd.org/cgi/man.cgi?query=mld&manpath=FreeBSD+10.1-RELEASE>

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