tcp ip 试题

（1）What were the two challenges of creating a network model (Select two)？A. interconnectivityB. interactionC. internetworkingD. interoperability（2）What is the function of CSMA/CD？A. It passes a token around a star topologyB. Nodes access the network and retransmit if they detect a collisionC. Nodes connect to a dual ring of fiber-optics and use a token-passing schemeD. Nodes break the frames into tiny cells and forward them through acell-switching network.（3）Given the subnet mask 255.255.240.0 on a Class A address, how many bits are allocated to subnetting？A. 4B. 5C. 9D. 12（4）在一个局域网上从主机A向主机B发送一封电子邮件，在开始发送电子邮件以前，必须对数据进行封装。

下面哪一项最好的描述了在生成一个分组以后所发生的事情？A．分组被沿着介质传送B．分组被放到一个帧中C．该分组被分段为若干帧D．该分组被转分为二进制格式（5）在TCP/IP模型中，那一层处理关于可靠性、流量控制和错误校正等问题？A．应用层B．传输层C．Internet层D．网络访问层（6）在数据通信设备环境中，我们常用的光纤波长有：A．850nmB．1310nmC．1490nmD．1550nmE．以上全都有（7）IEEE子层和OSI参考模型中的那层相关？A．2和3B．1和2C．3和4D．1和3（8）IEEE子层中的LLC，执行什么功能____A．加密B．封装C．分组D．以上全部（9）那些功能与帧有关______A．确定那些计算机在相互通信B．不同计算机之间的通信信号的开始时间和结束时间C．出错帧的标志D．以上全部（10）下面那一个第二层数据链路层的重要功能A．逻辑链路控制B．寻址C．介质访问控制D．以上全部（11）Which of the following services uses a process called windowing？A. Reliable data transferB. Connection-oriented virtual circuitC. Buffered transferD. ResequencingE. Multiplex ingF. Efficient, full-duplex transmissionG. Flow control（12）What is UDP ？A. An API that makes the transport layer independentB. A connectionless, unreliable transport protocolC. An API that allows multiple applications to share a network connectionD. A function that makes remote procedures appear to be local（13）ICMP、I P、ARP and RARP of the IP protocol suite map to：A. OSI layers 1 and 2B. OSI layer 5C. OSI layer 3D. OSI layer 2（14）Which layer is most important in providing reliable data ex change between two systems？A. Physical layerB. Data link layerC. Session layerD. Transport layer（15）Which of the following does TCP provide？A. Unreliable data streamB. Connectionless virtual circuitC. Flow controlD. Structured byte stream movement（16）Of the following, which field is not a part of the TCP header？A. Subnet maskB. Sequence numberC. Data offsetD. Destination port（17）What is a port？A. An API that makes the transport layer independentB. An API that allows multiple applications to share a network connectionC. A function that makes remote procedures appear to be localD. The point where upper-layer processes access transport layer services （18）What is ICMP？A. It is a network layer protocol that handles control messagesB. It is a network layer protocol that resolves addressesC. It is a session layer API that makes remote procedures transparent to a userD. It is a transport layer function for unreliable transport（19）What is the sequence number in a TCP header used for？A. AcknowledgmentsB. Reordering of the octets receivedC. Rejecting duplicate octetsD. All of the above（20）Variable sliding windows provide an ex plicit mechanism for notifying TCP if an intermediate node (for ex ample, a router) becomes congested。

A. TrueB. False（21）Which of the following parameters is not a part of UDP header？A. Source portB. Urgent pointerC. ChecksumD. LengthE. Destination port（22）What are the two basic mechanisms that make up a routing protocol？A. Route selectionB. FloodingC. Autonomous SystemsD. Data Tr a n s m i s s i o n（23）What types of information can be found in different types of routing protocol routing tables？(select 3)A. The destination network associated with the nex t hopB. The destination network associated with the cost metricC. The destination network associated with the subnet maskD. The destination network associated with the nex t path or interface to use （24）What is a static route？A. A static route is one that has been manually entered into the routing table andis not updated by a routing protocolB. A static route is one that is recomputed whenever a change is made on theinternetworkC. A static route is one that is redistributed when it has been learned by anotherrouting protocolD. A static route is one that comes already configured in the router from themanufacturer（25）What is an autonomous system？A. An areaB. A domainC. A contiguous set of routers defined within a larger internetwork, that do notshare routing information with the ex ternal internetworkD. All of the aboveE. None of the above（26）When a router receives a packet, it accepts or rejects a packet by examining what？A. The MAC address of the source of the packetB. The address of the source network/node numberC. The address of the destination network/nodeD. The MAC address of the nex t router（27）What do link-state protocols use as a metric？A. HopsB. CostC. CPU usageD. Network operational time（28）Flooding in link-state protocol means what？A. A router sending all routing information to its neighborsB. A router broadcasting all information to all routers in the networkC. The neighbors of a link-state router receiving a link-state packet, copying it,and then forwarding it to the rest of the networkD. A router sending information about the routers that have changed（29）Which statement is true of Interior Gateway Protocols？A. They apply to Internet domainsB. They apply to autonomous systems within the networkC. They apply to ex ternal networksD. They allow systems in the Internet to manage areas in the network where IGP isi m p l e m e n t e d（30）Ex terior Gateway Protocols are known as：A. Inter-domainB. AreasC. DomainsD. Intra-domain（31）Which of the following is used to calculate metric in Interior Gateway Routing Protocol？A. Internetwork delayB. BandwidthC. LoadD. ReliabilityE. All of the above（32）以太网的帧有那几种类型？A. Ethernet_IIB. Ethernet_802.2C. Ethernet_802.3D. Ethernet_SNAP（33）What essential reasons make OSPF better than RIP1?A. OSPF can select paths based on bandwidthB. Link-State protocols generally have faster convergence thanDistance-VectorC. OSPF supports VLSMD. OSPF has no hop count limitation because it is based on path cost（34）What is a BGP peer?A. A BGP neighbor that the router has formed a TCP connection withB. Another BGP router that the router is currently speaking withC. Another BGP router that the router is unable to speak withD. A BGP neighbor that the router has a broken TCP connection with（35）Which of the following are true of BGP?a. IBGP is used between the ASb. IBGP is used within the ASc. EBGP is used between the ASd. EBGP is used within the AS（36）An OSPF stubby or totally stubby Area can only exist if adjacent to which of the following?a. LSAb. LSPc. BDRd. ABRe. DRf. LSU（37）What is the most effective way to reduce large routing tables?a. Route filtersb. CIDR summary blocksc. Compressiond. Switching（38）By default, how does BGP handle IGP routes?a. BGP automatically redistributes all IGP routesb. BGP advertisements are independent of IGP route propagationc. GBP must wait until the IGP has propagated routing information across theautonomous systemd. BGP can immediately advertise routes without waiting until the IGP haspropagated information across the autonomous system（39）Which of the following BGP Path Attributes (metrics) is not a proprietary enhancement?a. Communityb. Originc. Aggregatord. Weight（40）Which of the following correctly describes an OSPF Area Border Router?a. It is used to connect various OSPF Areasb. It is used only at the outside edge of an OSPF network for protocol translationc. It is used only internally for OSPF to EIGRP redistributiond. It is used for routing protocol redistribution（41）When BGP routers with the same AS number ex change information, this is known as ____?a. BGPb. EBGPc. IGRPd. IBGP（42）Which of the following are characteristics of the BGP routing protocol?a. Link-state protocolb. Interior gateway protocolc. Ex terior gateway protocold. Distance-Vector protocol（43）Which of the following is untrue of routers running internal BGP?a. Routers are running IBGP when two BGP speaking routers are in differentAS’sb. They must form a TCP port 179 connection with each otherc. They do not have to be directly connectedd. Routers are running IBGP when two BGP speaking routers are in the same AS （44）Which of the following are true of a network design with a high number of OSPF routers in a single area?a. Increased problems with routing table ‘black holes’b. Increased SPF algorithm re-calculation timesc. Decreased OSPF update traffic overheadd. Increased OSPF update traffic overhead（45）What is included in an OSPF DBD/DDP?a. SPF entries from the OSPF routing tableb. STP entries from the OSPF spanning treec. LSA entries from the OSPF master router’s link-state databased. Database Description Packets（46）Which of the following are true regarding an OSPF internal router?a. Internal routers are in more than one areab. At least one interface is in Area 0c. All interfaces are in the same Aread. Internal routers redistribute routing information with routers in other areas（47）Which route types are passed by an OSPF ABR into a Totally Stubby Area?a. Generate Type 3-4b. Generate Type 5c. Generate 0.0.0.0d. Generate Type 1-2（48）Which of the following are true of Route Reflectors?a. The reduce the size of the BGP tableb. They enable the use of Route Summarizationc. They reduce the number of TCP sessionsd. They modify Split Horizon（49）Which of these OSPF statements are correct?a. OSPF com putes cost based on the interface’s bandwidth settingb. OSPF is not limited to a hop count metricc. OSPF uses LSA packets instead of broadcastsd. OSPF sends the complete routing table inside of each LSA packet（50）Which defined OSPF LSA types are Summary?a. Generate Type 5b. Generate 0.0.0.0c. Generate Type 1-2d. Generate Type 3-4（51）What is the BGP MED used for?a. Setting the route maps peer IDb. Setting IGP synchronizationc. Setting the route reflectors peer IDd. Setting a preferred return-pathway back into the originating AS（52）You are trying to deploy a large BGP network but notice that configuring BGP for full mesh will kill your router’s RAM and CPU. What can be configured to fix the problem?a. Route Mapsb. Route Redistributionc. Full Mesh neighbor statementsd. Route Reflectors（53）Which OSPF external metric type is additive (ie, includes all physical hops in cost calculation)?a. Type 2b. Type 3c. Type 4d. Type 1（54）Which of the following are the well-known Mandatory BGP Path Attributes?a. AS-pathb. Originc. Communityd. Nex t-hop（55）Which of the following is true of OSPF ABR?a. ABR’s are always in more than one areab. At least one interface is in Area 0c. It redistributes routing information with routers in other areasd. All interfaces are in the same Area（56）What types of routes can an OSPF totally stubby ABR send into the stubby area?（57）BGP peers are also known as______?a. Neighborsb. Route-Mapsc. Summariesd. MED’s（58）How many subnetworks and hosts per subnet are available in the network 151.17.18.0 with subnet mask 255.255.192.0?a. 4 subnets with 32,382 hosts eachb. 8 subnets with 8094 hosts eachc. 8 subnets with 16,384 hosts eachd. 2 subnets with 16,382 hosts each（59）During the final stages of OSPF convergence, when can the OSPF router begin to send user data?a. Ex changeb. Loadingc. 2-wayd. Full（60）Which of the following is untrue regarding routers running ex ternal BGP?a. They must form a TCP port 179 connection with each otherb. Routers are running EBGP when two BGP speaking routers are in the s ameASc. They should be directly connectedd. Routers are running EBGP when two BGP speaking routers are in differentAS’s（61）After the DR and BDR have been elected and master/slave adjacencies are established, OSPF routers use what method for network discov er?a. 2-wayb. initc. Loadingd. Ex change（62）Your routing tables are getting very large and you need to configure route summarization. How many Class C Internet addresses can you summarize with a /20 CIDR block?a. 2b. 4c. 8d. 16（63）What is the major shortcoming of using default IBGP full-meshconfigurations?a. The MED will be ignoredb. Compatibility problemsc. Route maps become mandatoryd. It does not scale（64）Is BGP connection-oriented or connection-less, and what protocol transport does it use?a. Connection-oriented/TCPb. Connection-oriented/UDPc. Connection-less/TCPd. Connection-less/UDP（65）Which of the following are true of full-duplex ethernet?a. There is a significant performance increase over half-duplex ethernetb. More collisionsc. If one host is transmitting, the other must wait for it to finishd. No collisionse. Clients must have a full-duplex compatible ethernet card（66）Which of the following are true of gigabit ether?a. 1000BaseT uses 2 pairsb. 1000BaseCX operates over UTP copperc. 1000BaseT operates over Cat5 UTPd. 1000Base SX operates over multi mode fiber（67）A LAN segmented with layer 2 switches has which of the following characteristics?a. Segmentation occurs at Layer 4 of the OSI modelb. Segmentation occurs at Layer 3 of the OSI modelc. Segmentation occurs at Layer 2 of the OSI modeld. A LAN segmented with layer 2 switches provides fewer users per segment（68）How does spanning tree determine which switch is the root?a. It picks the switch with the highest MAC addressb. It picks the switch with the lowest MAC addressc. It picks the switch with the lowest bridge IDd. The first bridge to boot is the root（69）At what layer of the seven layer OSI model do VLANs occur?a. Networkb. Datalinkc. Transportd. Session（70）Which of the following correctly matches OSI model layers with the names of data units?a. Frames are layer 2, packets are layer 4, and segments are layer 3b. Frames are layer 2, packets are layer 3, and segments are layer 4c. Frames are layer 3, packets are layer 2, and segments are layer 4d. Frames are layer 3, packets are layer 4, and segments are layer 2（71）How many bytes does the 802.1Q vlan-tag labelA. 4B. 8C. 1D. 2（72）Which one of these PPP authentication methods will send usernames and passwords as clear-tex t strings?a. chatb. chapc. natd. pap。