ADTRAN 1000R Series ip mcast-stub helper-address <ip address>

Command Reference Guide Global Configuration Mode Command Set

ip mcast-stub helper-address <ip address>

Use the ip mcast-stub helper-address command to specify an IP address toward which IGMP host reports

and leave messages are forwarded. This command is used in IP multicast stub applications in conjunction

with the ip mcast-stub downstream and ip mcast-stub upstream commands. Use the no form of this

command to return to default.

Syntax Description

<ip address> Specifies the address to which the IGMP host reports and leave messages are

forwarded.

Default Values

By default, no helper -a dd re ss is config u re d.

Applicable Platforms

This command applies to the NetVanta 300, 1000R, 3000, 4000, and 5000 and Total Access 900 Series

units.

Command History

Release 7.1 Command was introduced.

Functional Notes

The helper address is config ured globally and applies to all multicast-stub downstream interfaces . Th e

address specified may be the next upstr eam hop or any upstream address on the distribution tree for the

multicast source, up to and including the multicast source. The router selects, from the list of multicas t-stub

upstream 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 the

downstream interface(s). Th e router retransmits these reports with addresses set as if the report originated

from the selected upstream interface.

For example, if the router receives multiple joins for a group, it will not send any extra joins out the

upstream interface. Also, if it receives a leave, it will not send a leave until it is certain that there are no

more subscribers on any downstream interface.

Usage Examples

The following example specifies 172.45.6.99 as the helper address:

(config)#ip mcast-stub helper-address 172.4 5.6.99