Cisco Nexus 7000 Series Configuration Manual page 46

Configuring an IGMP SSM Translation
The SSM translation configures source addresses per Virtual Routing and Forwarding (VRF) mode on the
device to be mapped to specific SSM group ranges received in an IGMP report. The MRIB creates the (S,G)
state rather than (*, G) state.
The IGMP SSM-Translation works in the following way:
• When an IGMPv1 or IGMPv2 report is received on an interface, the IGMP querier performs a translation
table search for the reporting group.
• If there are configured source entries for the reporting group, the IGMP process adds to the interface that
the report is received on to an (Si,G) entry corresponding to each configured source Si. These entries are
stored in the MRIB for software and hardware multicast forwarding.
• If there are no configured source entries for the reporting group, the IGMP process adds to the interface
that the report is received on to an (*,G) entry in the MRIB. This is the typical IGMP functionality.
• The periodic group reports helps to keep the state of the translated (S,G) alive. If there are no incoming
reports, all entries time out at the same time.
• If an IGMPv2 leave message is received for the group and a corresponding translated entry exist, all
entries expire at the same time unless an overriding report is received.
Procedure
Step 1
Step 2
Step 3
Step 4
Step 5
Cisco Nexus 7000 Series NX-OS Multicast Routing Configuration Guide
32
Command or Action
configure terminal
Example:
Device# configure terminal
Device(config)#
ip igmp ssm-translate group-prefix
source-addr
Example:
Device(config)# ip igmp ssm-translate
232.0.0.0/8 10.1.1.1
show running-configuration igmp
Example:
Device(config)# show
running-configuration igmp
show ip igmp groups
Example:
Device(config)# show ip igmp groups
show ip mroute
Example:
Purpose
Enters configuration mode.
Configures the translation of IGMPv1 or
IGMPv2 membership reports by the IGMP
process to create the (S,G) state as if the router
had received an IGMPv3 membership report.
(Optional) shows the running-configuration
information, including ssm-translate command
lines.
(Optional) Displays the IGMP attached group
membership for a group or interface, the default
VRF, a selected VRF, or all VRFs.
(Optional) Shows IP multicast routing table for
default VRF.
Configuring IGMP