Restrictions for IGMP State Limit
You can configure only one global limit per device and one limit per interface.
Information About IGMP State Limit
IGMP State Limit
The IGMP State Limit feature allows for the configuration of IGMP state limiters, which impose limits on
mroute states resulting from IGMP membership reports (IGMP joins) on a global or per interface basis.
Membership reports exceeding the configured limits are not entered into the IGMP cache. This feature can
be used to prevent DoS attacks or to provide a multicast CAC mechanism in network environments where all
the multicast flows roughly utilize the same amount of bandwidth.
IGMP state limiters impose limits on the number of mroute states resulting from IGMP, IGMP v3lite, and
URL Rendezvous Directory (URD) membership reports on a global or per interface basis.
Note
Related Topics
Configuring Global IGMP State Limiters, on page 351
Configuring IGMP State Limiters Example, on page 354
IGMP State Limit Feature Design
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Configuring IGMP state limiters in global configuration mode specifies a global limit on the number of
IGMP membership reports that can be cached.
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Configuring IGMP state limiters in interface configuration mode specifies a limit on the number of
IGMP membership reports on a per interface basis.
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Use ACLs to prevent groups or channels from being counted against the interface limit. A standard or
an extended ACL can be specified. A standard ACL can be used to define the (*, G) state to be excluded
from the limit on an interface. An extended ACLs can be used to define the (S, G) state to be excluded
from the limit on an interface. An extended ACL also can be used to define the (*, G) state to be excluded
from the limit on an interface, by specifying 0.0.0.0 for the source address and source wildcard--referred
to as (0, G)--in the permit or deny statements that compose the extended access list.
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You can only configure one global limit per device and one limit per interface.
Mechanics of IGMP State Limiters
The mechanics of IGMP state limiters are as follows:
IP Multicast Routing Configuration Guide, Cisco IOS XE Release 3SE (Catalyst 3650 Switches)
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OL-29890-01
IP Multicast Optimization: IGMP State Limit
Restrictions for IGMP State Limit
