Enabling Ip Multicast Routing; Setting The Multicast Helper Address - HP 7102dl - ProCurve Secure Router Configuration Manual

Configuring Multicast Support for a Stub Network
Configuring IGMP Proxy for Multicast Stub Routing Support
12-12
You can also:
have the router stack join an IGMP group
alter IGMP intervals (for experienced administrators only)

Enabling IP Multicast Routing

The ProCurve Secure Router must implement multicast routing to keep track
of which interfaces forward packets destined to certain multicast addresses.
By default, multicast routing is disabled.
From the global configuration mode context, enter:
ProCurve(config)# ip multicast-routing
When multicast routing is enabled, the router stores a list of multicast routes.
The router creates an entry for each multicast address for which a host group
exists on a downstream network. All entries include a single incoming inter-
face, which is the upstream interface. An active entry also includes one or
more outgoing interfaces, which are the downstream interfaces through
which multicasts received on the incoming interface should be forwarded.

Setting the Multicast Helper Address

The helper address is the address to which all downstream interfaces forward
the IGMP reports and leave messages that they receive from connected hosts.
The helper address can be any upstream interface between the downstream
interface and the multicast source. It is often a router at an organization's
headquarters that runs a multicast routing protocol.
To the helper address, the local router sends one report and one leave message
for each active multicast group. As far as the device at the helper address is
concerned, the local router is a multicast host, and the helper device routes
the appropriate multicasts to it.
Set the global helper address by entering:
Syntax: ip mcast-stub helper-address <A.B.C.D>
The router can only have one multicast helper address. (This is why you can
only configure IGMP proxy for multicast support if all multicasts will be
received from the same next-hop router.)