Restrictions For Igmp State Limit; Information About Igmp State Limit; Igmp State Limit; Igmp State Limit Feature Design - Cisco Catalyst 3850 series Configuration Manual

Restrictions for IGMP State Limit

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
Note
URL Rendezvous Directory (URD) membership reports on a global or per interface basis.
Related Topics
Configuring Global IGMP State Limiters, on page 389
Configuring IGMP State Limiters Example, on page 392

IGMP State Limit Feature Design

• Configuring IGMP state limiters in global configuration mode specifies a global limit on the number of
• Configuring IGMP state limiters in interface configuration mode specifies a limit on the number of
• Use ACLs to prevent groups or channels from being counted against the interface limit. A standard or
• 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 3.6E (Catalyst 3850 Switches)
388
IGMP membership reports that can be cached.
IGMP membership reports on a per interface basis.
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.
IP Multicast Optimization: IGMP State Limit
OL-32598-01