Troubleshooting Ipv6 Multicast Routing And Forwarding; Abnormal Termination Of Ipv6 Multicast Data - 3Com MSR 50 Series Configuration Manual

Troubleshooting IPv6
Multicast Routing and
Forwarding
Abnormal Termination
of IPv6 Multicast Data
To do...
Display the RPF route
information of the
specified IPv6 multicast
source
Display the minimum
hop limit required for
an IPv6 multicast packet
to be forwarded
Clear forwarding entries
from the IPv6 multicast
forwarding table
Clear routing entries
from the IPv6 multicast
routing table
c
CAUTION:
The reset command clears the information in the IPv6 multicast forwarding
■
table or the multicast routing table, and thus may cause transmission failure of
IPv6 multicast information.
When a forwarding entry is deleted from the IPv6 multicast forwarding table,
■
the corresponding routing entry will also be deleted from the IPv6 multicast
routing table.
When a routing entry is deleted from the IPv6 multicast routing table, the
■
corresponding forwarding entry will also be deleted from the IPv6 multicast
forwarding table.
Symptom
A host sends an MLD report announcing its joining an IPv6 multicast group (G).
■
However, there is no member information about the IPv6 multicast group (G)
on the immediate router. The intermediate router can receive IPv6 multicast
packets successfully, but the packets cannot reach the stub network.
The interface of the intermediate router receives the IPv6 multicast packets, but
■
there is no corresponding (S, G) entry in the IPv6 PIM routing table.
Analysis
Before forwarding an IPv6 multicast packet, the router decrements the hop
■
limit value in the IPv6 packet header by 1 and recalculates the checksum.
Subsequently, the router forwards the IPv6 multicast packet to all outgoing
interfaces. If the multicast ipv6 minimum-hoplimit command is executed on
the outgoing interfaces, the hop limit value in the IPv6 packet header must be
no less than the configured minimum hop limit value. Otherwise, the packet
will be discarded.

Troubleshooting IPv6 Multicast Routing and Forwarding

Use the command...
display multicast ipv6 rpf-info
ipv6-source-address
[ ipv6-group-address ]
display multicast ipv6
minimum-hoplimit [ interface-type
interface-number ]
reset multicast ipv6 forwarding-table
{ { ipv6-source-address [ prefix-length ] |
ipv6-group-address [ prefix-length ] |
incoming-interface { interface-type
interface-number | register } } * | all }
reset multicast ipv6 routing-table
{ { ipv6-source-address [ prefix-length ] |
ipv6-group-address [ prefix-length ] |
incoming-interface { interface-type
interface-number | register } } * | all }
1215
Remarks
Available in any view
Available in any view
Available in user view
Available in user view