Reverse Path Forwarding (RPF) JN0-664 Practice Questions (Page 1)

Questions 1–5

1. 1application · medium

   A network engineer is explaining the purpose of RPF to a junior engineer. The junior engineer asks why RPF is necessary in multicast routing. What is the primary reason for RPF?

   • ATo prevent loops and duplicate packets in multicast forwarding.
   • BTo ensure that multicast packets are forwarded only on interfaces with multicast enabled.
   • CTo ensure that multicast packets are forwarded only to receivers that have joined the group.
   • DTo ensure that multicast packets are forwarded only on the shortest path to the source.
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2. 2foundation · easy

   What is a common fallback mechanism when an RPF check fails because there is no specific unicast route to the source?

   • ADropping the packet and sending an ICMP error to the source
   • BUsing the default route for the RPF check
   • CForwarding the packet to the multicast group's rendezvous point
   • DFlooding the packet out all interfaces
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4. 3foundation · easy

   Which Junos command displays the RPF state for multicast routes?

   • Ashow pim rpf
   • Bshow route multicast
   • Cshow multicast rpf
   • Dshow multicast route extensive
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5. 4foundation · easy

   During the RPF check, how does a router determine the expected incoming interface for a multicast packet?

   • ABy performing a unicast route lookup on the source address and using the outgoing interface of the longest-match route
   • BBy looking up the multicast group address in the multicast routing table
   • CBy checking the interface on which the packet was received against the multicast group's designated router
   • DBy using the interface with the highest IP address that is up
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6. 5application · medium

   A multicast network is experiencing packet loss. The network uses OSPF as the unicast routing protocol. A router is receiving multicast traffic on interface ge-0/0/0, but the OSPF route to the source points out ge-0/0/1. The engineer suspects an RPF issue. What is the most likely cause of the RPF failure?

   • AThe OSPF route to the source has a high metric.
   • BThe multicast group is not registered with the OSPF protocol.
   • CThe multicast traffic is arriving on a different interface than the OSPF route's outgoing interface.
   • DThe OSPF route to the source is not the best route in the routing table.
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