Protocol for establishing multicast group memberships on IPv4 networks

<span class="mw-page-title-main">Internet Group Management Protocol</span>

Internet Group Management Protocol

<p>The <b>Internet Group Management Protocol</b> (<b>IGMP</b>) is a <a href="/en/Communications_protocol" title="Communications protocol" class="mw-redirect wl">communications protocol</a> used by <a href="/en/Host_(network)" title="Host (network)" class="wl">hosts</a> and adjacent <a href="/en/Router_(computing)" title="Router (computing)" class="wl">routers</a> on <a href="/en/IPv4_network" title="IPv4 network" class="mw-redirect wl">IPv4 networks</a> to establish multicast group memberships. IGMP is an integral part of <a href="/en/IP_multicast" title="IP multicast" class="wl">IP multicast</a> and allows the network to direct multicast transmissions only to hosts that have requested them.</p>

<div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none" about="#mwt1">Protocol for establishing multicast group memberships on IPv4 networks</div>
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<p>IGMP can be used for one-to-many networking applications such as online <a href="/en/Streaming_video" title="Streaming video" class="mw-redirect wl">streaming video</a> and <a href="/en/Online_game" title="Online game" class="wl">gaming</a>, and allows more efficient use of resources when supporting these types of applications.</p>

<p>IGMP is used on <a href="/en/IPv4" title="IPv4" class="mw-redirect wl">IPv4</a> networks. Multicast management on <a href="/en/IPv6" title="IPv6" class="wl">IPv6</a> networks is handled by <a href="/en/Multicast_Listener_Discovery" title="Multicast Listener Discovery" class="wl">Multicast Listener Discovery</a> (MLD) which is a part of <a href="/en/ICMPv6" title="ICMPv6" class="wl">ICMPv6</a> in contrast to IGMP's bare IP encapsulation.</p>



The Internet Group Management Protocol is a communications protocol used by hosts and adjacent routers on IPv4 networks to establish multicast group memberships. IGMP is an integral part of IP multicast and allows the network to direct multicast transmissions only to hosts that have requested them. IGMP can be used for one-to-many networking applications such as online streaming video and gaming, and allows more efficient use of resources when supporting these types of applications. IGMP is used on IPv4 networks. Multicast management on IPv6 networks is handled by Multicast Listener Discovery which is a part of ICMPv6 in contrast to IGMP's bare IP encapsulation. 