Edge-Core ECS4660-28F, Руководство по управлению, Страница: 835 / 2020

C
HAPTER
21
| Multicast Routing
Configuring PIM for IPv4
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P
ARAMETERS
These parameters are displayed:
Common Attributes
◆
VLAN – Layer 3 VLAN interface. (Range: 1-4094)
◆
Mode – PIM routing mode. (Options: Dense, Sparse, None)
◆
IP Address – Primary IP 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)
◆
Hello Interval – Sets the frequency at which PIM hello messages are
transmitted out on all interfaces. (Range: 1-65535 seconds;
Default: 30 seconds)
Hello messages are sent to neighboring PIM routers from which this
device has received probes, and are used to verify whether or not these
neighbors are still active members of the multicast tree. PIM-SM
routers use these messages not only to inform neighboring routers of
their presence, but also to determine which router for each LAN
segment will serve as the Designated Router (DR).
When a router is booted or first configured to use PIM, it sends an initial
hello message, and then sets its Hello timer to the configured value. If
a router does not hear from a neighbor for the period specified by the
Hello Holdtime, that neighbor is dropped. This hold time is included in
each hello message received from a neighbor. Also note that hello
messages also contain the DR priority of the router sending the
message.
If the hello holdtime is already configured, and the hello interval is set
to a value longer than the hello holdtime, this command will fail.
◆
Join/Prune Holdtime – Sets the hold time for the prune state.
(Range: 1-65535 seconds; Default: 210 seconds)
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PIM-DM: The multicast interface that first receives a multicast
stream from a particular source forwards this traffic to all other
PIM-DM interfaces on the router. If there are no requesting groups
on that interface, the leaf node sends a prune message upstream
and enters a prune state for this multicast stream. The prune state
is maintained until the join/prune holdtime timer expires or a graft
message is received for the forwarding entry.
■
PIM-SM: The multicast interface that first receives a multicast
stream from a particular source forwards this traffic only to those
interfaces on the router that have requests to join this group. When
there are no longer any requesting groups on that interface, the leaf
node sends a prune message upstream and enters a prune state for
this multicast stream. The protocol maintains both the current join