Igmp Proxying - HP A5500 SI Switch Series Configuration Manual

As shown in
and IGMPv3 respectively. To provide SSM service for all the hosts if it is infeasible to run IGMPv3 on
Host A and Host B, you must configure the IGMP SSM mapping feature on Router A.
With the IGMP SSM mapping feature configured, when Router A receives an IGMPv1 or IGMPv2
report, it checks the multicast group address G carried in the message and does the following:
If G is not in the SSM group range, Router A cannot provide the SSM service but can provide the
•
ASM service.
If G is in the SSM group range but no IGMP SSM mappings that correspond to the multicast group
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G have been configured on Router A, Router A cannot provide SSM service and drops the
message.
If G is in the SSM group range and the IGMP SSM mappings have been configured on Router A
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for multicast group G, Router A translates the (*, G) information in the IGMP report into (G,
INCLUDE, (S1, S2...)) information based on the configured IGMP SSM mappings and provides
SSM service.
NOTE:
The IGMP SSM mapping feature does not process IGMPv3 reports.
For more information about the SSM group range, see the chapter "PIM configuration."

IGMP proxying

In some simple tree topologies, it is not necessary to configure complex multicast routing protocols, such
as PIM, on the boundary devices. Instead, you should configure IGMP proxying on these devices. With
IGMP proxying configured, the device serves as a proxy for the downstream hosts to send IGMP
messages, maintain group memberships, and implement multicast forwarding based on the
memberships. In this case, each boundary device configured with IGMP proxying is a host but no longer
a PIM neighbor to the upstream device.
Figure 32 Network diagram for IGMP proxying
Proxy & Querier
Router B
Receiver
Host A
Query from Router A
Report from Router B
Query from Router B
As shown in
Figure 31, on an SSM network, Host A, Host B, and Host C are running IGMPv1, IGMPv2,
Querier
Router A
Ethernet
Host B
Figure 32, the following types of interfaces are defined on an IGMP proxy device:
PIM domain
Receiver
Host C
Report from Host
Host interface
Router interface
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