Reference Guide

Internet Group Management Protocol (IGMP) | 351
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Internet Group Management Protocol (IGMP)
Internet Group Management Protocol (IGMP) is supported on the following platforms:
s z
Multicast identifies many hosts by a single destination IP address; hosts represented by the same IP address
are a multicast group. Internet group management protocol (IGMP) is a Layer 3 multicast protocol that
hosts use to join or leave a multicast group. Multicast routing protocols (such as Protocol independent
multicast [PIM]) use the information in IGMP messages to discover which groups are active and to
populate the multicast routing table.
IGMP Implementation Information
• FTOS supports IGMP versions 1, 2, and 3 based on RFCs 1112, 2236, and 3376, respectively.
• FTOS does not support IGMP version 3 and versions 1 or 2 on the same subnet.
• IGMP on FTOS supports up to 95 interfaces on the S-Series, and an unlimited number of groups on all
platforms.
• Dell Networking systems cannot serve as an IGMP host or an IGMP version 1 IGMP Querier.
• FTOS automatically enables IGMP on interfaces on which you enable a multicast routing protocol.
IGMP Protocol Overview
IGMP has three versions. Version 3 obsoletes and is backwards-compatible with version 2; version 2
obsoletes version 1.
Note: The S4810 supports up to 95 interfaces.