Dell Brocade DCX, Configuration Manual

Page: 649 / 1436

BigIron RX Series Configuration Guide 577
53-1001810-01
Adding an interface to a multicast group
23
Adding an interface to a multicast group
You can manually add an interface to a multicast group. This is useful in the following cases:
•
Hosts attached to the interface are unable to add themselves as members of the group using
IGMP.
•
There are no members for the group attached to the interface.
When you manually add an interface to a multicast group, the Brocade device forwards multicast
packets for the group but does not itself accept packets for the group.
You can manually add a multicast group to individual ports only. If the port is a member of a virtual
routing interface, you must add the ports to the group individually.
To manually add a port to a multicast group, enter a command such as the following at the
configuration level for the port.
BigIron RX(config-if-e10000-1/1)# ip igmp static-group 224.2.2.2
This command adds port 1/1 to multicast group 224.2.2.2.
To add a port that is a member of a virtual routing interface to a multicast group, enter a command
such as the following at the configuration level for the virtual routing interface.
BigIron RX(config-vif-1)# ip igmp static-group 224.2.2.2 ethernet 5/2
This command adds port 5/2 in virtual routing interface 1 to multicast group 224.2.2.2.
Syntax: [no] ip igmp static-group <ip-addr> [ethernet <slot>/<portnum> ]
The <ip-addr> parameter specifies the group number.
The ethernet <slot> / <portnum> parameter specifies the port number. Use this parameter if the
port is a member of a virtual routing interface, and you are entering this command at the
configuration level for the virtual routing interface.
Manually added groups are included in the group information displayed by the following
commands:
•
show ip igmp group
•
show ip pim group
IGMP v3
The Internet Group Management Protocol (IGMP) allows an IPV4 system to communicate IP
Multicast group membership information to its neighboring routers. The routers in turn limit the
multicast of IP packets with multicast destination addresses to only those interfaces on the router
that are identified as IP Multicast group members.
In IGMP V2, when a router sent a query to the interfaces, the clients on the interfaces respond with
a membership report of multicast groups to the router. The router can then send traffic to these
groups, regardless of the traffic source. When an interface no longer needs to receive traffic from a
group, it sends a leave message to the router which in turn sends a group-specific query to that
interface to see if any other clients on the same interface is still active.