Black Box LGB6026A, Руководство по управлению

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C
HAPTER
48 | Multicast Routing Commands
PIM Multicast Routing
◆
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.
◆
Sparse-mode interfaces 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 Rendezvous Point
(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 Shortest Path Source Tree (SPT), they periodically send
join messages toward the source. They also send prune messages
toward the RP to prune the shared path if they have already connected
to the source through the SPT, or if there are no longer any group
members connected to the interface.
E
XAMPLE
Console(config)#interface vlan 1
Console(config-if)#ip pim dense-mode
Console#show ip pim interface
PIM is enabled.
Vlan 1 is up.
PIM Mode : Dense Mode
IP Address : 192.168.0.2
Hello Interval : 30 sec
Hello HoldTime : 105 sec
Triggered Hello Delay : 5 sec
Join/Prune Holdtime : 210 sec
Lan Prune Delay : Disabled
Propagation Delay : 500 ms
Override Interval : 2500 ms
Graft Retry Interval : 3 sec
Max Graft Retries : 3
State Refresh Ori Int : 60 sec
Console#
ip pim hello-
holdtime
This command configures the interval to wait for hello messages from a
neighboring PIM router before declaring it dead. Use the
no form to restore
the default value.
S
YNTAX
ip pim hello-holdtime seconds
no ip pim hello-interval
seconds - The hold time for PIM hello messages. (Range: 1-65535)
D
EFAULT
S
ETTING
105 seconds