下列关于RPF（Reverse Path Forwarding）的说法正确的是（）

A.RPF的全称为Reverse Path Forwarding;

B.RPF的转发依据是报文的目的地址和单播路由表;

C.PRF的转发依据是报文的源地址和单播路由表;

D.RPF和具体的某种单播路由协议是无关的。

A.Reverse Path Forwarding

B.Reverse Path Flooding

C.Router Protocol Filter

D.Routing Protocol File

E.以上全不是

A. AS path

B. Split horizon

C. Poison reverse

D. Unicast RPF check

A. The router sent an IGMP version 2 query out interface Ethernet1 at multicast address 224.0.0.1.

B. Router RTA received an IGMP report version 1 from host 192.168.9.1.

C. Reverse Path Forwarding (RPF) is ena bled for 192.168.9.4.

D. Reverse Path Forwarding (RPF) is enabled for 224.0.1.40.

E. The IP multicast groups are 224.0.0.1, 224.0.1.40, and 239.255.0.1.

F. IP PIM RP mapping is static.

A. Sparse mode multicast uses a pull model to send multicast traffic to where it is requested

B. Dense mode multicast uses a push model to flood traffic throughout the network and then prunes the unwanted traffic

C. Dense mode multicast requires explicit join messa ges from their members

D. Sparse mode uses reverse path forwarding (RPF) to prune off redundant flows

E. The primary use of sparse mode multicast is for test labs and router performance testing

ter s in the network. Hosts on Network A receive the multicast traffic. However, hosts on Network B do not. On the basis of outputs provided, what could be the cause of the problem？ （）

A. The route to 224.69.15.0/24 will be out Ethernet 0

B. The reverse path forwarding (RPF) for the route 224.2.0.1 failed to find the interface on which the multicast packet was rece ived

C. Multicast route to 224.69.15.0/24 was added to the mroute table and created by a source directly connected to the router

D. Multicast route to 10.16.0.0/16 was added to the mroute table and created by a source directly connected to the router

E. This router received an IGMP host report from a group member or a PIM join message

A.Reverse protocol forwarding

B.Reverse protocol flooding

C.Reverse path forwarding

D.Reverse path flooding

A. reverse path of the RRO

B. least cost to the ingress router

C. shortest path to the egress router

D. reverse path of the path vector TLV

A. DVMRP hold-time period

B. Rendezvous point election

C. reverse path forwarding checks

D. interdomain multicast next hops

组播路由选择算法有泛洪法（flooding)，支撑树（spanning tree)算法，反向路径广播（reverse path

组播路由选择算法有泛洪法（flooding)，支撑树(spanning tree)算法，反向路径广播(reverse path broadcasting，RPB)算法，修剪的反向路径广播(truncated reverse pathbroadcasting，TRPB)算法，Steiner树，基于核心树的组播(core-basedtree，CBT)，请简要描述各算法的缺点。