Outgoing Interface List - HP 7102dl - ProCurve Secure Router Configuration Manual

A router should never have an (S, G) entry without an incoming interface.
ProCurve# show ip mroute
IP Multicast Routing Table
Flags:
bit Set,
F - Register, R - RP-bit Set
Timers: Uptime/Expires
(*, 239.255.255.1), 01:06:23/00:00:00, RP 10.1.1.1, Flags: SCJ
(*, G) entry
(192.168.100.2, 239.255.255.1), 00:12:10/00:03:30, Flags: ST
(S, G) entry
Figure 13-20. Incoming Interface for a Multicast Route

Outgoing Interface List

You can view the outgoing interface list for an entry to determine to which
neighbors the router is forwarding multicast traffic. (See Figure 13-21.)
The outgoing interface list for a (*, G) entry deals with the RP tree. It displays
the interfaces through which the router forwards the multicasts that it
receives from its upstream RP neighbor. An RP forwards decapsulated register
packets to the outgoing interfaces.
The outgoing interface list for an (S, G) entry deals with the SP tree. It displays
the interfaces through which the router must forward multicast packets sent
by a specific source. When a router creates a (S, G) entry, it copies the outgoing
interface list from the corresponding (*, G) entry. In this way, downstream
neighbors in the process of switching to the SP tree themselves continue to
receive traffic.
Note that the router will discard any multicast packets from this source that
do not arrive on the incoming interface listed for the entry—for example,
packets received from an RP neighbor. This means that once a router has
created an (S, G) entry for a multicast group and set its STP-bit, it will only
accept and send traffic for this group over the SP tree.
S - Sparse, C - Connected, P - Pruned, J - Join SPT, T - SPT-
Incoming interface: Null, RPF nbr 0.0.0.0
Incoming interface: fr 1.3, RPF nbr 10.3.3.2
Multicasts that
Configuring Multicast Support with PIM-SM
The address for
the upstream
match this
RPF neighbor.
source and
address must
be received on
this interface.
Troubleshooting PIM-SM
13-53