User's Manual

Configuring the Firewall
Configuring Advanced Firewall Settings
Cisco RV180/RV180W Administration Guide 95
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DRAFT - CISCO CONFIDENTIAL
Configuring Internet Group Management Protocol (IGMP)
Internet Group Management Protocol (IGMP) is an exchange protocol for routers.
Hosts that want to receive multicast messages need to inform their neighboring
routers of their status. In some networks, each node in a network becomes a
member of a multicast group and receives multicast packets. In these situations,
hosts exchange information with their local routers using IGMP. Routers use IGMP
periodically to check if the known group members are active. IGMP provides a
method called dynamic membership by which a host can join or leave a multicast
group at any time.
The Allowed Networks table lists all the allowed networks configured for the
device and allows several operations on the allowed networks:
• Network Address—The network address from which the multicast packets
originate.
• Mask Length— Mask Length for the network address.
In this table you can perform the following actions:
• Check Box—Select all the allowed networks in the table.
• Delete—Deletes the selected allowed network or allowed networks.
• Add—Opens the Allowed Network Configuration page to add a new
network.
• Edit—Opens the Allowed Network Configuration page to edit the selected
network.
NOTE By default the device will forward multicast packets which are originating from its
immediate WAN network.
Adding Allowed Networks
To configure IGMP:
STEP 1 Choose Firewall > Advanced Settings > IGMP Configuration.
STEP 2 Check the Enable box to allow IGMP communication between the router and other
nodes in the network.