Brocade Multi-Service IronWare Multicast Configuration Guide (Supporting R05.6.00) - Manual (Page 130)

118 Multi-Service IronWare Multicast Configuration Guide
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IGMP V3
1
Syntax: show ip igmp [vrf vrf-name] settings
The vrf parameter specifies that you want to display IGMP settings information for the VRF
specified by the vrf-name variable.
The report shows the following information:
Source-specific multicast
Using the Any-Source Multicast (ASM) service model, sources and receivers register with a
multicast address. The protocol uses regular messages to maintain a correctly configured
broadcast network where all sources can send data to all receivers and all receivers get broadcasts
from all sources.
With Source-specific multicast (SSM), the “channel” concept is introduced where a “channel”
consists of a single source and multiple receivers who specifically register to get broadcasts from
that source. Consequently, receivers are not burdened with receiving data they have no interest in,
and network bandwidth requirements are reduced because the broadcast need only go to a
sub-set of users. The address range 232/8 has been assigned by the Internet Assigned Numbers
Authority (IANA) for use with SSM.
IGMP V3 and source specific multicast protocols
When IGMP V3 and PIM Sparse (PIM-SM) is enabled, the source specific multicast service (SSM)
can be configured. SSM simplifies PIM-SM by eliminating the RP and all protocols related to the RP.
IGMPv3 and PIM-SM must be enabled on any ports that you want SSM to operate.
Configuring PIM SSM group range
PIM Source Specific Multicast (SSM) is a subset of the PIM SM protocol. In PIM SSM mode, the
shortest path tree (STP) is created at the source. The STP is created between the receiver and
source, but the STP is built without the help of the RP. The router closest to the interested receiver
host is notified of the unicast IP address of the source for the multicast traffic. PIM SSM goes
directly to the source-based distribution tree without the need of the RP connection. PIM SSM is
different from PIM SM because it forms its own STP tree, without forming a shared tree. The
multicast address group range is 232.0.0.0/8.
To configure a single SSM group address, enter the following command under the router pim
configuration:
TABLE 27 show ip igmp output
This field Displays
Query Interval How often the router will query an interface for group membership.
Configured Query Interval The query interval that has been configured for the router.
Max Response Time The length of time in seconds that the router will wait for an IGMP (V1 or V2)
response from an interface before concluding that the group member on
that interface is down and removing it from the group.
Group Membership Time The length of time in seconds that a group will remain active on an interface
in the absence of a group report.
Configured Version The IGMP version configured on the router.
Operating Version The IGMP version operating on the router.