Command Reference Guide Global Configuration Mode Command Set61200510L1-35E Copyright © 2005 ADTRAN 434ip mcast-stub helper-address Use the ip mcast-stub helper-address command to specify an IP address toward which IGMP host reportsand leave messages are forwarded. This command is used in IP multicast stub applications in conjunctionwith the ip mcast-stub downstream and ip mcast-stub upstream commands. Use the no form of thiscommand to return to default.Syntax Description Specifies the address to which the IGMP host reports and leave messages areforwarded.Default ValuesBy default, no helper-address is configured.Applicable PlatformsThis command applies to the NetVanta 300, 1000R, 3000, 4000, and 5000 and Total Access 900 Seriesunits.Command HistoryRelease 7.1 Command was introduced.Functional NotesThe helper address is configured globally and applies to all multicast-stub downstream interfaces. Theaddress specified may be the next upstream hop or any upstream address on the distribution tree for themulticast source, up to and including the multicast source. The router selects, from the list of multicast-stubupstream interfaces, the interface on the shortest path to the specified address. The router then proxies,on the selected upstream interface (using an IGMP host function), any host joins/leaves received on thedownstream interface(s). The router retransmits these reports with addresses set as if the report originatedfrom the selected upstream interface.For example, if the router receives multiple joins for a group, it will not send any extra joins out theupstream interface. Also, if it receives a leave, it will not send a leave until it is certain that there are nomore subscribers on any downstream interface.Usage ExamplesThe following example specifies 172.45.6.99 as the helper address:(config)#ip mcast-stub helper-address 172.45.6.99
