1dedecb47SBruce M Simpson.\" 2dedecb47SBruce M Simpson.\" Copyright (c) 2009 Bruce Simpson. 3dedecb47SBruce M Simpson.\" 4dedecb47SBruce M Simpson.\" Redistribution and use in source and binary forms, with or without 5dedecb47SBruce M Simpson.\" modification, are permitted provided that the following conditions 6dedecb47SBruce M Simpson.\" are met: 7dedecb47SBruce M Simpson.\" 1. Redistributions of source code must retain the above copyright 8dedecb47SBruce M Simpson.\" notice, this list of conditions and the following disclaimer. 9dedecb47SBruce M Simpson.\" 2. Redistributions in binary form must reproduce the above copyright 10dedecb47SBruce M Simpson.\" notice, this list of conditions and the following disclaimer in the 11dedecb47SBruce M Simpson.\" documentation and/or other materials provided with the distribution. 12dedecb47SBruce M Simpson.\" 3. Neither the name of the project nor the names of its contributors 13dedecb47SBruce M Simpson.\" may be used to endorse or promote products derived from this software 14dedecb47SBruce M Simpson.\" without specific prior written permission. 15dedecb47SBruce M Simpson.\" 16dedecb47SBruce M Simpson.\" THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 17dedecb47SBruce M Simpson.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18dedecb47SBruce M Simpson.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19dedecb47SBruce M Simpson.\" ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 20dedecb47SBruce M Simpson.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21dedecb47SBruce M Simpson.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22dedecb47SBruce M Simpson.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23dedecb47SBruce M Simpson.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24dedecb47SBruce M Simpson.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25dedecb47SBruce M Simpson.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26dedecb47SBruce M Simpson.\" SUCH DAMAGE. 27dedecb47SBruce M Simpson.\" 28c51ff413SAndrey V. Elsukov.Dd April 8, 2013 29dedecb47SBruce M Simpson.Dt MLD 4 30dedecb47SBruce M Simpson.Os 31dedecb47SBruce M Simpson.Sh NAME 32dedecb47SBruce M Simpson.Nm mld 33dedecb47SBruce M Simpson.Nd Multicast Listener Discovery Protocol 34dedecb47SBruce M Simpson.Sh SYNOPSIS 35dedecb47SBruce M Simpson.In sys/types.h 36dedecb47SBruce M Simpson.In sys/socket.h 37dedecb47SBruce M Simpson.In netinet/in.h 38dedecb47SBruce M Simpson.In netinet/in_systm.h 39dedecb47SBruce M Simpson.In netinet/ip6.h 40dedecb47SBruce M Simpson.In netinet/icmp6.h 41dedecb47SBruce M Simpson.In netinet6/mld6.h 42dedecb47SBruce M Simpson.Ft int 43dedecb47SBruce M Simpson.Fn socket AF_INET6 SOCK_RAW IPPROTO_ICMPV6 44dedecb47SBruce M Simpson.Sh DESCRIPTION 45dedecb47SBruce M Simpson.Tn MLD 46dedecb47SBruce M Simpsonis a control plane protocol used by IPv6 hosts and routers to 47dedecb47SBruce M Simpsonpropagate multicast group membership information. 48dedecb47SBruce M SimpsonNormally this protocol is not used directly, except by the kernel 49dedecb47SBruce M Simpsonitself, in response to multicast membership requests by user 50dedecb47SBruce M Simpsonapplications. 51dedecb47SBruce M SimpsonMulticast routing protocol daemons may open a raw socket to directly 52dedecb47SBruce M Simpsoninteract with 53dedecb47SBruce M Simpson.Nm 54dedecb47SBruce M Simpsonand receive membership reports. 55dedecb47SBruce M Simpson.Pp 56dedecb47SBruce M SimpsonAs of 57dedecb47SBruce M Simpson.Fx 8.0 , 58dedecb47SBruce M SimpsonMLD version 2 is implemented. 59dedecb47SBruce M SimpsonThis adds support for Source-Specific Multicast (SSM), whereby 60dedecb47SBruce M Simpsonapplications may communicate to upstream multicast routers that 61dedecb47SBruce M Simpsonthey are only interested in receiving multicast streams from 62dedecb47SBruce M Simpsonparticular sources. 63dedecb47SBruce M SimpsonThe retransmission of state-change reports adds some robustness 64dedecb47SBruce M Simpsonto the protocol. 65dedecb47SBruce M Simpson.\" 66dedecb47SBruce M Simpson.Sh SYSCTL VARIABLES 67dedecb47SBruce M Simpson.Bl -tag -width indent 68dedecb47SBruce M Simpson.\" 69dedecb47SBruce M Simpson.It net.inet6.mld.ifinfo 70dedecb47SBruce M SimpsonThis opaque read-only variable exposes the per-link MLDv2 status to 71dedecb47SBruce M Simpson.Xr ifmcstat 8 . 72dedecb47SBruce M Simpson.\" 73dedecb47SBruce M Simpson.It net.inet6.mld.gsrdelay 74dedecb47SBruce M SimpsonThis variable specifies the time threshold, in seconds, for processing 75dedecb47SBruce M SimpsonGroup-and-Source Specific Queries (GSR). 76dedecb47SBruce M SimpsonAs GSR query processing requires maintaining state on the host, 77dedecb47SBruce M Simpsonit may cause memory to be allocated, and is therefore a potential 78dedecb47SBruce M Simpsonattack point for Denial-of-Service (DoS). 79dedecb47SBruce M SimpsonIf more than one GSR query is received within this threshold, 80dedecb47SBruce M Simpsonit will be dropped, to mitigate the potential for DoS. 81dedecb47SBruce M Simpson.\" 82dedecb47SBruce M Simpson.It net.inet6.mld.v1enable 83dedecb47SBruce M SimpsonIf this variable is non-zero, then MLDv1 membership queries (and host 84dedecb47SBruce M Simpsonreports) will be processed by this host, and backwards compatibility 85dedecb47SBruce M Simpsonwill be enabled until the v1 'Older Version Querier Present' timer expires. 86dedecb47SBruce M SimpsonThis sysctl is normally enabled by default. 87dedecb47SBruce M Simpson.\" 88dedecb47SBruce M Simpson.El 89dedecb47SBruce M Simpson.Sh SEE ALSO 90*2a2a1074SJoel Dahl.Xr netstat 1 , 91*2a2a1074SJoel Dahl.Xr sourcefilter 3 , 92c51ff413SAndrey V. Elsukov.Xr icmp6 4 , 93dedecb47SBruce M Simpson.Xr inet 4 , 94dedecb47SBruce M Simpson.Xr multicast 4 , 95*2a2a1074SJoel Dahl.Xr ifmcstat 8 96dedecb47SBruce M Simpson.Sh HISTORY 97dedecb47SBruce M SimpsonThe 98dedecb47SBruce M Simpson.Nm 99dedecb47SBruce M Simpsonmanual page appeared in 100dedecb47SBruce M Simpson.Fx 8.0 . 101