This guide describes basic and advanced IGMP and MLD configuration, including an overview of IGMP/MLD, definitions of some of the IGMP/MLD terminology, examples and discussion of the most common IGMP functionality, examples and discussion of the advanced functionality available through the feature-rich IGMP/MLD implementation in AlliedWare Plus™, information for debugging, information about the STP state of the simple three-switch ring used in most examples, and information about IGMPv3/MLDv2.