Mld Troubleshooting Help; Mld Snooping; Introduction To Mld Snooping - Planet XGS3-42000R User Manual

XGS 3-42000R(config) #ipv6 pim multicast-routing
XGS 3-42000R(config) #ipv6 pim rp-address 3FFE::1
XGS 3-42000R(config) #interfac e vlan1
XGS 3-42000R(Config-if-Vlan1) #ipv6 address 3FFE::2/64
XGS 3-42000R(Config-if-Vlan1) #ipv6 pim sparse-mode
XGS 3-42000R(Config-if-Vlan1) #exit
XGS 3-42000R(config) #interfac e vlan2
XGS 3-42000R(Config-if-Vlan2) #ipv6 address 3FFA::1/64
XGS 3-42000R(Config-if-Vlan2) #ipv6 pim sparse-mode
XGS 3-42000R(Config-if-Vlan2) #ipv6 mld query-timeout 150

44.6.4 MLD Troubleshooting Help

When configuring and using MLD protocol, MLD protocol may fail to work normally due to physical
connections, incorrect configuration and so on. So, users shall note the following points:

Assure the physical connection is correct.

Assure the protocol of interface and link is UP (use show interface command)

Assure to start one kind of multicast protocol on the interface

Assure the time of the timers of each router on the same network segment is consistent; usually we
recommend the default setting.

Unicast route shall be used to carry out RPF examination for multicast protocol. So the correctness of
unicast route shall be guaranteed above all.
If all attempts fail to solve the problems on MLD, please use debug commands such as debug ipv6 MLD
event/packet, and copy DEB UG information in 3 minutes and send to Tec hnology Service Center.

44.7 MLD Snooping

44.7.1 Introduction to MLD Snooping

MLD, the Multicast Listener Discovery Protoc ol, is used to realize multicasting in the IP v6. MLD is used by the
network equipments such as rout ers which supports multicast for multicast listener discovery, also used by
listeners looking forward to join certain multicast group informing the router to receive data packets from
certain multicast address, all of which are done through MLD message exchange. First the router send an
MLD Multicast listener Query message through a multicast address which can address all the listeners
(namely ff02::1). Once there is a listener who wishes to join the multicast address, it will send a MLD Multicast
listener Report back through the multicast address.
MLD S nooping is namely the MLD listening. The switch restricts the multicast traffic from flooding through
MLD Snooping, and forward the multicast traffic to ports associated to multicast devices only. The switch
listens to the MLD messages bet ween multicast routers and listeners, and maintains the multicast group
forwarding list bas ed on the listening result. The switches forwards multicast packets according to the
multicast forwarding list
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