3. Troubleshooting Functional Failures in Operation633.8 IPv4 Multicast Routing Communication FailureActions to be taken if IPv4 multicast communication failures occur on this system are described below.3.8.1 Communication on IPv4 PIM-SM Network Is DisabledIf multicast relay is disabled in the IPv4 PIN-SM network configuration, isolate the cause according to the failureanalysis method below.The figure below illustrates a network example of IPv4 PIM-SM.Figure 3-11: Example of IPv4 PIM-SM NetworkNote• BSR: This router delivers rendezvous point information (for details, see the manual "Configuration Settings").• Rendezvous point router: This router relays the packets, for which the relay destination is not determined, towardthe multicast receiver (for details, see the manual "Configuration Settings").• first-hop-router: This router is directly connected to the multicast sender.• last-hop-router: This router is directly connected to the multicast receiver.(1) Common check itemsThe table below shows the common check items for all system in the IPv4 PIM-SM network configuration.Table 3-22: Common Check ItemsNo. Troubleshooting Steps and Command Action1 Confirm that the use of multicast function is designated (ipmulticast routing) in the configuration.show running-configIf the use of multicast function is not designated, correct theconfiguration.2 Confirm that PIM is running on one or more interfaces.show ip pim interfaceIf PIM is not running, check the configuration. Set PIM to runon one or more interfaces. If the interface set in theconfiguration to run PIM is not displayed by the show ippim interface command, confirm that multi-homing isnot set on the interface.3 Check to see if IGMP snooping is applied to the interfaceswith PIM enabled.show igmp-snoopingIf IGMP snooping is applied, confirm the following:• Confirm the port to which the neighboring router connectedis set as multicast router port of IGMP snooping.• See "3.5.4 Multicast Relay by IGMP snooping IsDisabled."MulticastMulticastdatasenderBSR and rendezvous pointrouterMulticastreceiverMulticastsenderParticipation inthe IGMP groupParticipation inthe IGMP groupfirst-hop-routerlast-hop-router
