NEC IP8800/S3600, IP8800/S6600 manual Multicast Data Is Double-relayed on IPv4 PIM-SSM Network

3. Troubleshooting Functional Failures in Operation

No.	Troubleshooting Steps and Command	Action
5	If there is an interface in which the relay target group	If this system is not DR, check DR of the relay target interface.
	participates, confirm that this system is DR.
	show ip pim interface
6	Confirm that IGMP snooping is set to the interface with static	When the IGMP snooping is set, confirm the following:
	group join function enabled.	• Confirm that the relay port is set as a multicast router port
	show igmp-snooping	for IGMP snooping.
		• See "3.5.4 Multicast Relay by IGMP snooping Is
		Disabled."
7	Confirm that no interface in abnormal state is detected.	See notices and confirm that warning information is not
	show ip igmp interface	output. When warning information is output, check the
		following:
		• L: The number of join request exceeded expected
		maximum number. Check to see the number of connected
		users.
		• Q: The IGMP version of neighboring router is different.
		Adjust it to the version of IGMP.
		• R: A user who transmitted reports unreceivable at the
		present settings exists. Change the IGMP version of this
		system or confirm the setting of the participant.
		• S: Some of the participant information are being discarded
		because the number of source exceeded the upper limit
		defined to store source per message in IGMPv3. Check the
		settings of the participant.

(3) first-hop-router check items

The table below shows the items to be checked when this system is the first-hop-router in the IPv4 PIM-SSM network configuration.

Table 3-30: first-hop-router Check Items

No.	Troubleshooting Steps and Command	Action
1	Confirm that this system is directly connected to the multicast	If not, check the network configuration.
	sender.
2	Confirm that PIM or IGMP is running on the interface	If PIM or IGMP is not running, check the configuration and
	connected to the multicast sender.	set the configuration to run PIM or IGMP.
	show ip pim interface
	show ip igmp interface
3	Check to see if multicast data arrives at this system.	If multicast data has not arrived, check the setting of the
		multicast sender.
4	Check to see if the group address and source address in	If the group address and source address do not match, check
	multicast data match those in the multicast routing	the settings of the multicast sender and last-hop-router.
	information.
	show ip mroute
	show netstat multicast

3.8.4Multicast Data Is Double-relayed on IPv4 PIM-SSM Network

If multicast data is double-relayed in the IPv4 PIM-SSM network configuration, check the settings of each router and set the configuration to run PIM on the interface for a network having multiple routers.

If double-relay still continues, check the following:

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