Troubleshooting guide

3. Troubleshooting Functional Failures During Operation
107
network configuration.
Table 3-51: Items checked in common
No. Items to check and commands Action
1 Make sure that the setting for using the multicast
functionality (
ipv6 multicast routing) exists in the
configuration.
show running-config
If the setting for using the multicast functionality does
not exist, modify the configuration.
2 Make sure that the address setting for the loopback
interface exists in the configuration.
show running-config
If the address setting for the loopback interface does
not exist in the configuration, modify the
configuration.
3 Make sure that PIM is running on one or more
interfaces.
show ipv6 pim interface
If PIM is not running, check and modify the
configuration so that PIM runs on at least one of the
interfaces.
4 Check whether MLD snooping is set for the interface
on which PIM runs.
show mld-snooping
If MLD snooping is set, check the following:
• Check whether the multicast router port for MLD
snooping is set for the port connected to the
neighboring router.
• See 3.6.5 Multicast forwarding by MLD snooping
is not possible.
5 Make sure that the configuration does not contain
filtering or other settings that suppress forwarding of
protocol packets and multicast packets on the interface
on which PIM and MLD run.
show running-config
If the configuration contains a setting that suppresses
forwarding of protocol packets and multicast packets,
modify the configuration. For details about the
procedure for checking the filter configuration
information, see 3.25.1 Checking the filters and QoS
configuration information.
6 Check the PIM neighboring information.
show ipv6 pim neighbor
If neighboring routers are not displayed, check the
following:
• Use the
show ipv6 pim command with the
interface parameter to make sure that PIM is
running on the interface connected with the
neighboring routers.
• Check the settings of the neighboring routers.
7 Check whether the unicast route to the multicast data
sender exists.
show ipv6 route
If the unicast route does not exist, see 3.11 IPv6
unicast routing communication failures.
8 Make sure that PIM is running on the unicast route send
interface to the multicast data sender.
show ipv6 pim interface
If PIM is not running, check and modify the
configuration so that PIM runs on the unicast route
send interface.
9 Check the configuration to make sure that the
PIM-SSM group addresses contain the forwarding
target group address.
show running-config
If the PIM-SSM group addresses do not contain the
forwarding target group address, modify the
configuration.
10 Check whether multicast routing information exists.
show ipv6 mroute
If multicast routing information does not exist, check
the downstream router settings.
11 Check whether the number of the multicast routing
information entries or multicast forwarding entries
exceeds its upper limit.
For the multicast routing information:
show ipv6 mroute
For the multicast forwarding entries:
show ipv6 mcache
netstat multicast
If a warning is displayed, check whether an
unexpected multicast routing information entry or
unexpected multicast forwarding entry has been
created. If many negative caches are found among the
multicast forwarding entries, check whether there is a
terminal that is sending unnecessary packets.