Ericsson ECN330, User Manual

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Configuring the ECN330-switch
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1553-KDU 137 365 Uen D 2006-06-16
6.21.5.3 Configuring PIM-SM Interface Settings
To fully enable PIM-SM, multicast routing needs to be enabled globally for the
router (page 469), then enable PIM-SM globally for the router (page 492), and
also enable PIM-SM for each interface that will participate in multicast routing.
Command Usage
A PIM-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.
Command Attributes
• VLAN – VLAN interface. (Range: 1-4094; Default: VLAN 1)
• PIM-SM Protocol Status – Enables PIM-SM on the specified interface.
(Default: Disabled)
• PIM-SM must be enabled on each VLAN interface connected to the
PIM Sparse network. Internet Group Management Protocol (IGMP)
must also be enabled on each interface (see “Configuring IGMP
Interface Parameters” on page 364).
• Hello Interval (seconds) – Sets the interval at which periodic hellos
are sent out on all interfaces. (Range: 1-65535; Default: 30)
• PIM-SM routers send periodic hello messages to inform
neighboring routers of their presence, and to determine which
router for each LAN segment will serve as the Designated Router
(DR).
• When a router is booted or first configured for PIM-SM, 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 Hold Time (set to a period of 3.5 times the
Hello Interval by default), that neighbor is dropped. This hold time is
included in each hello message received from a neighbor. Also note