Border Gateway Protocol（BGP) is inter-autonomous system （71) protocol. BGP is based on a

A. stub

B. the autonomous system of an exte rior gateway protocol (EGP)

C. NSSA

D. totally stubby

E. the autonomous system of a different interior gateway protocol (IGP)

F. area 0

The Border Gateway Protocol(BGP)is an interautonomous system【S1】protoco1．The primary function of a BGP speaking system is to exchange network【S2】information withother BGP system．This network reachability information includes information on the list of Auton0．mous System(ASs)that reachability information traverses．BGP一4 provides a new set of mecha-nisms for supposing【S3】interdomain routing．These mechanisms include support for adver-tising an IP【S4】and eliminate the concept of network class within BGP．BGP-4 also intro-duces mechanisms that allow aggregation of routes，including【S5】of AS paths．These chan-ges provide support for the proposed supernettting schem

【S1】

A．connecting

B．resolving

C．routing

D．supernettting

● The Border Gateway Protocol (BGP) is an interautonomous system （71） protocol. The primary function of a BGP speaking system is to exchange network （72） information with other BGP system. This network reachability information includes information on the list of Autonomous System (ASs) that reachability information traverses. BGP-4 provides a new set of mechanisms for supporting （73） interdomain routing. These mechanisms include support for advertising an IP （74） and eliminate the concept of network class within BGP. BGP-4 also introduces mechanisms that allow aggregation of routes, including （75） of AS paths. These changes provide support for the proposed supernettting scheme.

（71）

A. connecting

B. resolving

C. routing

D. supernettting

（72）

A. secubility

B. reachability

C. capability

D. reliability

（73）

A. answerless

B. connectionless

C. confirmless

D. classless

（74）

A. prefix

B. suffix

C. infix

D. reflex

（75）

A. reservation

B. relation

C. aggregation

D. connection

●Border Gateway Protocol(BGP) is inter-autonomous system (71) protocol. BGP is based on a routing method called path vector routing. Distance vector routing is not a good candidate for inter-autonomous system routing because there are occasions on which the route with the smallest (72) count is not the preferred route. For example, we may not want a packet through an not secure even though it is the shortest route. Also, distance vector routing is unstable due to the fact that the routers announce only the number of hop counts to the destination without actually defining the path that leads to that (73) ．A router that recevives a distance vector advertisement packet may be fooled if the shortest path is actually calculated through the receiving router itself. Link (74) routing is also not a good candidate for inter-autonomous system routing because an Internet is usually too big for this routing method. To use link state routing for the whole internet would require each routex to have a huge link state database. It would also take a long time for each router to calculate its rousting (75) using the Dijkstra algorism.

（71）

A. routing

B. switching

C. transmitting

D. receiving

(72)

A. path

B. hop `

C. route

D. packet

(73）

A. connection

B. window

C. source

D. destination

(74)

A. status

B. search

C. state

D. research

(75）

A. table

B. state

C. metric

D. cost

A.0

B.10

C.60

D.120

A.0

B.10

C.60

D.120

B.这条路有一定是通过动态路由学习到的

B.这条路由项中的Proto可能是rip

D.这条路由一定不可能是一条直连路由