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IPv6 PIM configuration (available only on the
A5500 EI)
NOTE:
•
The term
router in this document refers to both routers and Layer 3 switches.
•
To facilitate description, the term
IPv6 PIM domain refers to a network that comprises IPv6 PIM–
capable routers in this document.
IPv6 PIM overview
Protocol Independent Multicast for IPv6 (IPv6 PIM) provides IPv6 multicast forwarding by leveraging
static routes or IPv6 unicast routing tables generated by any IPv6 unicast routing protocol, such as RIPng,
OSPFv3, IS-ISv6, or BGP4+. IPv6 PIM uses an IPv6 unicast routing table to perform reverse path
forwarding (RPF) check to implement IPv6 multicast forwarding.
Independent of the IPv6 unicast routing protocols that are running on the device, IPv6 multicast routing
can be implemented as long as the corresponding IPv6 multicast routing entries are created through IPv6
unicast routes. IPv6 PIM uses the RPF mechanism to implement IPv6 multicast forwarding. When an IPv6
multicast packet arrives on an interface of the device, it undergoes an RPF check. If the RPF check
succeeds, the device creates the corresponding routing entry and forwards the packet. If the RPF check
fails, the device discards the packet. For more information about RPF, see the chapter “IPv6 multicast
routing and forwarding configuration.”
Based on the implementation mechanism, IPv6 PIM falls into the following modes:
•
Protocol Independent Multicast–Dense Mode for IPv6 (IPv6 PIM-DM)
•
Protocol Independent Multicast–Sparse Mode for IPv6 (IPv6 PIM-SM)
•
Bidirectional Protocol Independent Multicast for IPv6 (IPv6 BIDIR-PIM)
•
Protocol Independent Multicast Source-Specific Multicast for IPv6 (IPv6 PIM-SSM)
IPv6 PIM-DM overview
IPv6 PIM-DM is a type of dense-mode IPv6 multicast protocol. It uses the push mode for IPv6 multicast
forwarding, and is suitable for small-sized networks with densely distributed IPv6 multicast members.
The basic implementation of IPv6 PIM-DM is as follows:
•
IPv6 PIM-DM assumes that at least one IPv6 multicast group member exists on each subnet of a
network. Therefore, IPv6 multicast data is flooded to all nodes on the network. Then, branches
without IPv6 multicast forwarding are pruned from the forwarding tree, leaving only those branches
that contain receivers. This flood-and-prune process takes place periodically. That is, pruned
branches resume IPv6 multicast forwarding when the pruned state times out. Data is flooded again
down these branches, and then the branches are pruned again.
Содержание A5500 EI Switch Series
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