
IGMP Multicast Commands
©2008 Allied Telesis Inc. All rights reserved.
Software Version 5.2.1
AlliedWare Plus
TM
Operating System Software Reference C613-50003-00 REV E
34.9
ip igmp limit
Use this command to configure the limit on the maximum number of group membership
entries for the device as a whole or for the specified interface (if in interface mode). Once the
specified number of group memberships is reached, all further membership reports will be
ignored. Optionally, you can configure an access-list to stop certain address(es) from being
subject to the limit.
The limit is dependent on the MTU (Maximum Transmission Unit) of the interface, which is the
size in bytes of the largest packet that a network protocol can transmit. Typically for an
ethernet channel with an MTU of 1500 the igmp group membership limit will be 183 groups,
because each igmp group membership is 8 bytes.
Use the
no
parameter with this command to unset the limit and any specified exception
access-list.
Syntax
ip igmp
limit
<limitvalue>
[
except
<accesslist>
]
no ip igmp
limit
Mode
Global Config mode and Interface mode
Usage
This command applies to interfaces configured for IGMP, IGMP Snooping, or IGMP Proxy.
Examples
The following example configures an IGMP limit of 100 group membership entries across all
interfaces on which IGMP is enabled, and excludes group 224.1.1.1 from this limitation:
The following example configures an IGMP limit of 100 group membership entries on vlan1:
Parameter
Description
<limitvalue>
<1-2097152>
Maximum number of group membership entries.
<accesslist>
<1-99>|<1300-1999>|
<word>
Number or name of the access list
that defines multicast groups that are not subject to the configured limit.
<1-99>
Access-list number
<1300-1999>
Access-list number (expanded range)
<word>
Standard IP access-list name
awplus#
configure terminal
awplus(config)#
access-list 1 224.1.1.1 0.0.0.0
awplus(config)#
ip igmp limit 100 except 1
awplus#
configure terminal
awplus(config)#
interface vlan1
awplus(config-if)#
ip igmp limit 100