Cisco ASA 5505 Configuration Manual page 458

Customizing Multicast Routing
Controlling Access to Multicast Groups
To control the multicast groups that hosts on the adaptive security appliance interface can join, perform
the following steps:
Step 1 In the main ASDM window, choose Configuration > Device Setup > Routing > Multicast > IGMP >
Access Group.
The Access Group pane appears. The table entries in the Access Group pane are processed from the top
down. Place more specific entries near the top of the table and more generic entries further down. For
example, place an access group entry that permits a specific multicast group near the top of the table and
an access group entry below that denies a range of multicast groups, including the group in the permit
rule. The group is permitted because the permit rule is enforced before the deny rule.
Double-clicking an entry in the table opens the
entry.
Step 2 Choose Add or Edit.
The Add Access Group or Edit Access Group dialog box appears. The Add Access Group dialog box
lets you add a new access group to the Access Group Table. The Edit Access Group dialog box lets you
change information for an existing access group entry. Some fields may be locked when editing existing
entries.
Choose the interface name that the access group is associated with from the Interface drop-down list.
Step 3
You cannot change the associated interface when you are editing an existing access group.
Choose permit from the Action drop-down list to allow the multicast group on the selected interface.
Step 4
Choose deny to filter the multicast group from the selected interface.
In the Multicast Group Address field, enter the address of the multicast group to which the access group
Step 5
applies.
Enter the network mask for the multicast group address, or choose one of the common network masks
Step 6
from the Netmask drop-down list.
Click OK.
Step 7
Limiting the Number of IGMP States on an Interface
You can limit the number of IGMP states resulting from IGMP membership reports on a per-interface
basis. Membership reports exceeding the configured limits are not entered in the IGMP cache and traffic
for the excess membership reports is not forwarded.
To limit the number of IGMP states on an interface,perform the following steps:
In the main ASDM window, choose Configuration > Device Setup > Routing > Multicast > IGMP >
Step 1
Protocol.
Choose the interface you want to limit from the table on the Protocol pane, and click Edit.
Step 2
The Configure IGMP Parameters dialog box appears.
In the Group Limit field, enter the maximum number of host that can join on an interface. Valid values
Step 3
range from 0 to 500. The default value is 500. Setting this value to 0 prevents learned groups from being
added, but manually defined memberships are still permitted.
Cisco ASA 5500 Series Configuration Guide using ASDM
24-8
Chapter 24
Add or Edit Access Group
Configuring Multicast Routing
dialog box for the selected
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