Web Management Guide-R06

Chapter 20 | Multicast Routing
Configuring PIMv6 for IPv6
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◆ PIMv6 and MLD proxy cannot be used at the same time. When an interface is
set to use PIMv6 Dense mode, MLD proxy cannot be enabled on any interface
of the device (see “MLD Proxy Routing” in the CLI Reference Guide). Also, when
MLD proxy is enabled on an interface, PIMv6 cannot be enabled on any
interface.
PIM6-DM
◆ PIM6-DM functions similar to DVMRP by periodically flooding the network with
traffic from any active multicast server. It also uses MLD to determine the
presence of multicast group members. The main difference, is that it uses the
router’s unicast routing table to determine if the interface through which a
packet is received provides the shortest path back to the source.
◆ Dense-mode interfaces are subject to multicast flooding by default, and are
only removed from the multicast routing table when the router determines
that there are no group members or downstream routers, or when a prune
message is received from a downstream router.
PIM6-SM
◆ A PIM6-SM interface is used to forward multicast traffic only if a join message is
received from a downstream router or if group members are directly connected
to the interface. When routers want to receive a multicast flow, they
periodically send join messages to the RP, and are subsequently added to the
shared path for the specified flow back up to the RP. If routers want to join the
source path up through the SPT, they periodically send join messages toward
the source. They also send prune messages toward the RP to prune the shared
path once they have connected to the source through the SPT, or if there are no
longer any group members connected to the interface.
Parameters
These parameters are displayed:
Common Attributes
◆ VLAN – Layer 3 VLAN interface. (Range: 1-4094)
◆ Mode – PIMv6 routing mode. (Options: Dense, None)
The routing mode must first be set to None, before changing between Dense
and Sparse modes.
◆ IPv6 Address – IPv6 link-local address assigned to the selected VLAN.
◆ Hello Holdtime – Sets the interval to wait for hello messages from a
neighboring PIM router before declaring it dead. Note that the hello holdtime
should be greater than or equal to the value of Hello Interval, otherwise it will
be automatically set to 3.5 x the Hello Interval. (Range: 1-65535 seconds;
Default: 105 seconds, or 3.5 times the hello interval if set)