NEC IP8800/S6600, IP8800/S3600 IPv4 Multicast Routing Communication Failure, Common check items

3. Troubleshooting Functional Failures in Operation

3.8IPv4 Multicast Routing Communication Failure

Actions to be taken if IPv4 multicast communication failures occur on this system are described below.

3.8.1Communication on IPv4 PIM-SM Network Is Disabled

If multicast relay is disabled in the IPv4 PIN-SM network configuration, isolate the cause according to the failure analysis method below.

The figure below illustrates a network example of IPv4 PIM-SM.

Figure 3-11: Example of IPv4 PIM-SM Network

BSR and rendezvous point		Multicast
router	Participation in
		receiver
	the IGMP group

Multicast
sender	first-hop-router

last-hop-router

Multicast

dataParticipation in the IGMP group

Multicast sender

Note

•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, toward the 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 items

The table below shows the common check items for all system in the IPv4 PIM-SM network configuration.

Table 3-22: Common Check Items

No.	Troubleshooting Steps and Command	Action
1	Confirm that the use of multicast function is designated (ip	If the use of multicast function is not designated, correct the
	multicast routing) in the configuration.	configuration.
	show running-config
2	Confirm that PIM is running on one or more interfaces.	If PIM is not running, check the configuration. Set PIM to run
	show ip pim interface	on one or more interfaces. If the interface set in the
		configuration to run PIM is not displayed by the show ip
		pim interface command, confirm that multi-homing is
		not set on the interface.
3	Check to see if IGMP snooping is applied to the interfaces	If IGMP snooping is applied, confirm the following:
	with PIM enabled.	• Confirm the port to which the neighboring router connected
	show igmp-snooping	is set as multicast router port of IGMP snooping.
		• See "3.5.4 Multicast Relay by IGMP snooping Is
		Disabled."

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