Which of the following technologies can be used in distance vector routing protocols to prevent routing loops?（）A、Spanning Tree ProtocolB、Shortest path first treeC、Link-state advertisements (LSA)D、Hold-down timersE、Split horizonF、VRP

A. Only routers can split boundaries (horizons) between concentric networks.

B. Each AS must keep routing tables converged to prevent dead routes from being advertised across boundaries.

C. Networks can only remain fully converged if all information is sent out all active interfaces.

D. Information about a route should not be sent back in the direction from which the original update came.

E. Distance vector protocols need fall back routers that are responsible for momentary loops.

A. Spanning Tree Protocol

B. Shortest path first tree

C. Link-state advertisements (LSA)

D. Hold-down timers

E. Split horizon

F. VRRP

根据下面的文字资料回答 71～75 题 n the following essay，each blank has four choices．Choose the most suitable one from the four choices and write down in the answer sheet．

Open Shortest Path First(OSPF)is a（ 1 ）routing algorithm that（ 2 ）work done on the OSI IS-IS intradomain routing protocol．This routing，as compared to distance-vector routing，requires（ 3 ）processing power．The Dijkstra algorithm is used to calculate（ 4 ）OSPF routing table updates only take place when necessary，（ 5 ）at regular intervals．

第6题：文中（ 1 ）处正确的答案是（ ）。

A．distance-vector

B．link-state

C．flow-based

D．selective flooding

A. Only router can split boundaries(horizons)between concentric networks.

B. All distance vector protocols require fall routes that may cause momentary loops as the topology changes.

C. Networks can only remain fully converged if all information about routes is sent out all active interfaces.

D. Information about a route should not be sent back in the direction from which the original update came.

E. Each AS must keep routing tables converged to prevent dead routes from being advertised across the AS boundary.

A. Distance vector protocols send the entire routing table to directly connected neighbors.

B. Distance vector protocols are responsible for sending updates to all networks listed in the routing table.

C. Link state protocols are responsible for sending the entire routing table to the whole network.

D. Link state protocols send updates regarding their own links status to all other routers on the network.

A. CIDR

B. Split horizon

C. Authentication

D. Classless masking

E. Hold-down timers

F. Multicast routing updates

G. Path Vectoring

A. inet.0

B. inet.1

C. inet.2

D. inet.3

A.Routing loops, hold down timers

B.Switching loops, split horizon

C.Routing loops, split horizon

D.Switching loops, VTP

E.Routing loops, STP

F.Switching loops, STP