Technical data

BLADE OS 5.1 Application Guide
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 Chapter 13: IGMP BMD00136, November 2009
IGMP Filtering
With IGMP Filtering, you can allow or deny a port to send and receive multicast traffic to certain
multicast groups. Unauthorized users are restricted from streaming multicast traffic across the
network.
If access to a multicast group is denied, IGMP Membership Reports from the port are dropped, and
the port is not allowed to receive IP multicast traffic from that group. If access to the multicast
group is allowed, Membership Reports from the port are forwarded for normal processing.
To configure IGMP Filtering, you must globally enable IGMP filtering, define an IGMP filter,
assign the filter to a port, and enable IGMP Filtering on the port. To define an IGMP filter, you must
configure a range of IP multicast groups, choose whether the filter will allow or deny multicast
traffic for groups within the range, and enable the filter.
Configuring the Range
Each IGMP Filter allows you to set a start and end point that defines the range of IP addresses upon
which the filter takes action. Each IP address in the range must be between 224.0.1.0 and
239.255.255.255.
Configuring the Action
Each IGMP filter can allow or deny IP multicasts to the range of IP addresses configured. If you
configure the filter to deny IP multicasts, then IGMP Membership Reports from multicast groups
within the range are dropped. You can configure a secondary filter to allow IP multicasts to a small
range of addresses within a larger range that a primary filter is configured to deny. The two filters
work together to allow IP multicasts to a small subset of addresses within the larger range of
addresses.
Note – Lower-numbered filters take precedence over higher-number filters. For example, the
action defined for IGMP Filter 1 supersedes the action defined for IGMP Filter 2.