Alcatel-Lucent 4A0-108 問題集

質問 1：
Click the exhibit.

What happens when Host 2 issues an IGMP report to join a group?
A. Only Router A gets this IGMP report, but no further action is taken, as Router A is not the PIM DR.
B. Both Router A and Router B get this IGMP report; Router B propagates a PIM join toward the core network.
C. Only Router A gets this IGMP report and propagates a PIM join toward the core network.
D. Both Router A and Router B get this IGMP report, and both propagate a PIM join toward the core network.
正解：B
解説: (Topexam メンバーにのみ表示されます)

質問 2：
Which of the following PIM messages are sent towards the RP? (Choose two)
A. (*, G) Join/Prune
B. (S, G) Join/Prune
C. (S, G, rpt) Join/Prune
D. Register Stop
正解：A,C

質問 3：
Refer to the exhibit.

Which one of the following descriptions is correct, assuming that all the IGMP join, PIM join and multicast traffic are for the same multicast group?
A. IGMP is enabled on Router A and B's interfaces facing the switch. PIM is enabled on Router A and B's interfaces facing the switch. IGMP snooping is not enabled on the switch.
B. IGMP is enabled on Router A and B's interfaces facing the switch. PIM is enabled on Router A and B's interfaces facing the switch. IGMP snooping is enabled on the switch.
C. IGMP is enabled on Router A and B's interfaces facing the switch. PIM is not enabled on Router A and B's interfaces facing the switch. IGMP snooping is not enabled on the switch.
D. IGMP is enabled on Router A and B's interfaces facing the switch. PIM is not enabled on Router A and B's interfaces facing the switch. IGMP snooping is enabled on the switch.
正解：C

質問 4：
In Draft Rosen, a PE router encapsulates customer multicast packets into provider packets. What source IP address is used for the provider packets?
A. The source IP address of the customer packet.
B. The system IP address of the originating PE router.
C. The outgoing interface IP address of the originating PE router.
D. The source IP address specified in the MVPN configuration.
正解：B

質問 5：
Which of the following conditions triggers the S-PMSI construction in Draft Rosen?
A. If multicast data exceeds the threshold set on the ingress PE, the S-PMSI is constructed.
B. If multicast data exceeds the threshold set on the egress PE, the S-PMSI is constructed.
C. If the number of interested receivers exceeds the threshold set on the ingress PE, the SPMSI is constructed.
D. If the number of interested receivers exceeds the threshold set on the egress PE, the SPMSI is constructed.
正解：A

質問 6：
How do the routers in the PIM domain become aware of the address of the elected BSR?
A. It is unicast to them
B. It is flooded through the network in a bootstrap message
C. It is preconfigured on all routers
D. It is flooded through the network in the PIM Hello
正解：B

質問 7：
What impact does an asymmetric IGP routing topology have on the PIM RPF check?
A. PIM does not work in an asymmetric topology, therefore there is no RPF check at all.
B. The PIM RPF check may fail, since traffic from the source may arrive on one interface, while the IP route to the source may point to another interface on the PIM router.
C. There is not enough information provided here to answer the question.
D. There is no impact, since the Shared and Source Path Trees are built from the receiver to the source.
正解：D