H3C Technologies H3C SecPath F1000-E - Manual (Page 39)

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• IS_EX: The source filtering mode is Exclude, namely, the report sender requests the multicast data
from any sources but those defined in the specified multicast source list.
• TO_IN: The filtering mode has changed from Exclude to Include.
• TO_EX: The filtering mode has changed from Include to Exclude.
• ALLOW: The Source Address fields in this Group Record contain a list of the additional sources that
the system wishes to hear from, for packets sent to the specified multicast address. If the change was
to an Include source list, these are the addresses that were added to the list; if the change was to
an Exclude source list, these are the addresses that were deleted from the list.
• BLOCK: The Source Address fields in this Group Record contain a list of the sources that the system
no longer wishes to hear from, for packets sent to the specified multicast address. If the change was
to an Include source list, these are the addresses that were deleted from the list; if the change was
to an Exclude source list, these are the addresses that were added to the list.
IGMP SSM Mapping
The IGMP SSM mapping feature allows you to configure static IGMP SSM mappings on the last hop
router to provide SSM support for receiver hosts running IGMPv1 or IGMPv2. The SSM model assumes
that the last hop router is aware of the desired multicast sources when receivers join multicast groups.
• When a host running IGMPv3 joins a multicast group, it can explicitly specify one or more multicast
sources in its IGMPv3 report.
• A host running IGMPv1 or IGMPv2, however, cannot specify multicast source addresses in its report.
In this case, you need to configure the IGMP SSM mapping feature to translate the (*, G)
information in the IGMPv1 or IGMPv2 report into (G, INCLUDE, (S1, S2...)) information.
Figure 3 Network diagram for IGMP SSM mapping
SSM
IGMPv1 report
IGMPv2 report
IGMPv3 report
Router A
Querier
Host A (IGMPv1) Host B (IGMPv2) Host C (IGMPv3)
Receiver Receiver Receiver
As shown in
Figure 3 , on an SSM network, Host A, Host B and Host C are running IGMPv1, IGMPv2 and
IGMPv3 respectively. To provide SSM service for all the hosts while 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:
• If G is not in the SSM group range, Router A cannot provide the SSM service but the ASM service.