题库精选:CCNA考试自测题第2卷
【简介】感谢网友“碳二氢五氧氢”参与投稿，下面是小编为大家带来的题库精选:CCNA考试自测题第2卷（共6篇），希望大家能够喜欢!
篇1：题库精选:CCNA考试自测题第2卷
下面的问题将帮助你评价在本章中学习到的内容。仔细阅读所有的选项，因为正确答案可能多于1个。选择每个问题中所有的正确答案。
1) company a has recently merged with company b, which exists in the same building and is physically close enough for all the computers to belong on the same network seg ment.
company a uses an atm backbone and fast ethernet for all nodes. company b has a token ring environment on shielded twisted-pair wiring. why will company a and company b select a router for their newly merged network (公司a最近合并了公司b，它们位于同一座大楼中，并且所有的计算机足够接近，可以属于同一个跳。公司a在所有的节点上使用at m主干和快速e t h e r n e t公司b使用屏蔽双绞线基础上的令牌环网环境。为什么公司a和公司b为它们新的合并网络选择了路由)？
a. network segment size has reached the maximum
b. network addresses are not sufficient for a merged network
c. tr a ffic must be segmented to prevent an expected bandwidth overload
d. a router is the usual way to connect dissimilar network types
2) what are the two basic mechanisms that make up a routing protocol (构成路由选择协议的两个基本机制是什么)？
a. route selection
b. flooding
c. autonomous systems
d. data tr a n s m i s s i o n
3) what is a routing table used for (路由选择表的用途是什么)？
a. it is the physical support for the router to sit on
b. it contains a list of all the timers used to prevent routing loops
c. it is used to select the best route
d. it manages the periodic update algorithm
4) what types of information can be found in different types of routing protocol routing tables (在不同类型的路由选择协议路由表中可以发现何种类型的信息)？(select 3)
a. the destination network associated with the next hop
b. the destination network associated with the cost metric
c. the destination network associated with the subnet mask
d. the destination network associated with the next path or interface to use
5) what is a routing update used for (路由选择更新的用途是什么)？
a. routing updates notify neighboring routers with a 呼叫
b. routing updates redistribute routes learned from other routing protocols
c. routing updates maintain the routing table
d. routing updates increase the network addresses available by changing the subnet masks
6) when a node on one network sends a packet to a node on another segment that is three
hops away, what addresses are included in the initial addressing of that packet (select 2) (当网络上的节点向另一个跳3个跳上的节点发送信息表时，在那个信息表的初始地址中包含了什么地址)？
a. the network address of the router
b. the mac layer address of the router
c. the network address of the destination node
d. the mac layer address of the destination node
7) what are three objectives for a routing protocol (路由选择协议的3个目标是什么)？
a. accuracy
b. quick holddowns
c. rapid convergence
d. low overhead
8) define convergence (定义收敛)。
a. convergence is the updates that are triggered by network changes
b. convergence is the process of sending 呼叫packets
c. convergence is two routers merging their routing tables into one
d. convergence is the synchronizing of all routing tables on the internetwork, or simply the synchronization of a single route change across all routers.
9) why are dynamic routing protocols considered dynamic (为什么动态路由选择协议考虑动态)？
a. because each route is dynamically selected for each packet with a destination network not attached to the router。
b. because new routes are dynamically recomputed whenever there is a change in the nternetwork topology
c. because convergence happens faster
d. because all the routes remain the same no matter what changes happen on the network
10) what is a static route (什么是静态路由)？
a. a static route is one that has been manually entered into the routing table and is not updated by a routing protocol
b. a static route is one that is recomputed whenever a change is made on the internetwork
c. a static route is one that is redistributed when it has been learned by another routing protocol
d. a static route is one that comes already configured in the router from the manufacturer
11) what type of network is best when using static routes (当使用静态路由时，何种类型的网络是最好的)？
a. a large network with hundreds of routers and networks
b. a complex internetwork that changes often
c. an autonomous system with multiple connections to other autonomous systems
d. a small network with few routers and infrequent changes
12) what is an autonomous system (什么是自治系统)？
a. an area
b. a domain
c. a contiguous set of routers defined within a larger internetwork, that do not share routing information with the external internetwork
d. all of the above
e. none of the above
13) what is a default route (什么是默认路由)？
a. a type of static route
b. a destination for any nonroutable packet
c. gateway of last resort
d. all of the above
e. none of the above
14) what type of information does a distance vector router build its routing table with (距离向量路由器用何种类型的信息来建立它的路由选择表)？
a. 呼叫packets
b. second-hand information
c. lsps
d. first-hand information
15) what is the count to infinity problem (什么是无限计数问题)？
a. a routing loop that results from the way distance vector protocols use second-hand information
b. the inability of routers to process more than 16 hops
c. the excessive cpu overhead presented by distance vector algorithms
d. the result of using both rip and igrp on the same internetwork
16) what is poison reverse (什么是破坏逆转)？
a. a change to the default update period timer
b. a routing loop that occurs when using second-hand information to update route tables
c. a router virus
d. a version of split-horizon that sends back a “route unreachable” update to the router that the route was learned from, in order to avoid routing loops
17) what is rip (什么是r i p )？
a. rip is an older distance vector interior gateway protocol with a 30-second update timer and . maximum of 15 hops (where “i n f i n i t y” is 16 hops)
b. rip is a new link-state protocol created by cisco
c. rip is a proprietary protocol created by cisco that has two versions; only version 2 is used currently
d. rip is a distance vector interior gateway protocol with a 224 maximum network diameter (maximum 224 hops)
18) what is igrp (什么是i g r p )？
a. igrp is an older distance vector interior gateway protocol with a 30-second update timer and a maximum of 15 hops (where infinity is 16 hops)
b. igrp is a new link-state protocol created by cisco
c. igrp is a proprietary protocol created by cisco that has two versions; only version 2 isused currently
d. igrp is a distance vector and interior gateway protocol with a 224 maximum network diameter (maximum 224 hops)
19) what is the purpose of a flash update in igrp (igrp中的瞬时更新的目的是什么)？
a. a flash update is a standard 90-second update
b. after three flash updates, a route is considered unreachable
c. a flash update is sent immediately upon a change in the network topology, in order to speed convergence
d. after seven flash updates, a route is removed from the routing table
20) how can the administrator change how igrp selects routes (管理员如何修改i g r p选择路由的方法)？
a. the administrator can set update timers
b. the administrator can enable or disable split horizon
c. the administrator can set up load balancing across redundant routes
d. the administrator can adjust the metric weights used for determining the route selection
21) the way to get traffic from one segment of the network to another segment is (在网段之间进行通信的方法是)：
a. bridging
b. routing
c. switching
d. all of the above
22) routing occurs at which layer (路由发生在哪一层)？
a. physical layer
b. data link layer
c. network layer
d. transport layer
23) in general, the bets route selected by a router is one with (一般而言，路由器选择的最佳路由具有何种特性)？
a. least cost
b. shortest distance
c. lowest metric value
d. none of the above
24) a routing table typically includes which of the following (路由表通常包含下列的哪些信息)？
a. destination network address
b. the total number of networks
c. the number of nodes in each network
d. the total number of routers in a network
25) when a router receives a packet, it accepts or rejects a packet by examining what (当路由器接受到数据包时，它通过检查什么而决定接受或拒绝数据包)？
a. the mac address of the source of the packet
b. the address of the source network/node number
c. the address of the destination network/node
d. the mac address of the next router
26) low overhead of a routing algorithm is normally associated with (路由选择算法的低代价通常和什么相关)？
a. optimal route
b. cpu usage
c. accuracy
d. converg e n c e
27) convergence is not an issue if (收敛并不会成为一个问题，如果)：
a. routers are added to the network
b. some of the network interfaces are down
c. cpu/bandwidth usage of the routers changes
d. an invariant network topology is selected for the network architecture
28) an internet protocol (ip) router selects (网际协议( i p )路由器选择)：
a. an entire path from source to destination
b. the next route step
c. the two adjacent routers to itself
d. all of the above.
29) ip route configuration command for a static route includes which of the following parameters (静态路由的ip route配置命令包括下列哪一个参数)？
a. subnetwork number of the destination network
b. subnet mask of the source network
c. ip address of the interface of the router which the packet should use
d. mac address of the next router on the path
30) given the following portion of the network:
network a→ router x→ router y→ network b
i n t e r f a c e : i n t e r f a c e : 8 6 . 0 . 0 . 0
x 0 y0
3 5 . 3 . 3 . 4
and assuming a network mask of 255.0.0.0 for both a and b networks, which one of the
following represents a correct command to configure router x to send data from network a to network b (给定网络的下列端口：
网络a→路由器x→路由器y→网络b
接口： 接口： 8 6 . 0 . 0 . 0
x 0 y 0
3 5 . 3 . 3 . 4
并假设a和b网络的网络掩码为2 5 5 . 0 . 0 . 0，则下面的哪一个代表了配置路由器x从网络a向网络b发送数据的正确命令)？
a. #ip route 85.0.0.0 255.0.0.0 35.3.3.3
b. #ip route 86.0.0.0 255.0.0.0 35.3.3.4
c. #ip route 86.0.0.0 255.0.0.0 35.3.3.3
d. #ip route 85.0.0.0 255.0.0.0 35.3.3.4
31) a static routing table can be changed at any time without manual intervention (静态路由选择表可以不经人工干预而在任何时候修改)。
a. true
b. false
32) in a hybrid solution of static and dynamic routing, the nonroutable packets are sent to (在静态和动态路由的混合解决方案中，不可路由的数据包发送到)：
a. the next router
b. the central router
c. the gateway of last resort
d. the source router where the packets originated
33) how is fault tolerance on a routing algorithm achieved (路由选择算法如何实现容错)？
a. by providing a central control router
b. by a distributed routing protocol
c. by load balancing of the traffic
d. all of the above
34) the configuration command ip defa u lt for a default static router requires which of the following parameters (默认静态路由器的配置命令ip defa u lt需要下列的哪一个参数)？
a. network mask
b. router interface number
c. subnet id
d. network number
35) in a distance vector routing protocol, aging is set for (在距离向量路由选择协议中，时 效为什么设置)？
a. only the next available router
b. all routing information
c. only the unavailable routers
d. only the routers in the lowest metric route
36) in a distance vector algorithm, the holddown interval for large or complex networks (在距离向量算法中，大型或复杂网络的暂停间隔)：
a. cannot be used
b. would need to have a much larger value
c. is equal to negative reachability parameter
d. would need to have a smaller value to reach converg e n c e
37) what do link-state protocols use as a metric (链路状态协议使用什么作为度)？
a. hops
b. cost
c. cpu usage
d. network operational time
38) flooding in link-state protocol means what (链路状态协议中的泛洪法意味着什么)？
a. a router sending all routing information to its neighbors
b. a router broadcasting all information to all routers in the network
c. the neighbors of a link-state router receiving a link-state packet, copying it, and then
forwarding it to the rest of the network
d. a router sending information about the routers that have changed
39) which statement is true of interior gateway protocols (对内部网关协议的陈述中，哪一 句是正确的)？
a. they apply to internet domains
b. they apply to autonomous systems within the network
c. they apply to external networks
d. they allow systems in the internet to manage areas in the network where igp is i m p l e m e n t e d
40) exterior gateway protocols are known as (外部网关协议又称为)：
a. inter-domain
b. areas
c. domains
d. intra-domain
41) routing information protocol (rip) can have maximum of (路由信息协议( r i p )最多可以具有多少个跳计数)？
a. 24 hops
b. 16 hops
c. 12 hops
d. 8 hops
42) how many commands are required to configure a router for rip (为路由器配置r i p需要多少个命令)？
a. four
b. three
c. two
d. one
43) rip authentication command can be used with which version of rip (rip鉴别可以和r i p的哪个版本一起使用)？
a. rip version 1
b. rip version 2
c. rip version 1 and rip version 2
d. none of the above
44) in the interior gateway routing protocol, a route is removed from the routing table after(在内部网关路由选择协议中，一个路由在多长时间之后从路由选择表中删除)？
a. three update periods
b. 60 seconds
c. five update periods
d. seven update periods
e. 90 seconds
45) which of the following is used to calculate metric in interior gateway routing protocol(下面的哪一个用于在内部网关路由协议中计算度？ )
a. internetwork delay
b. bandwidth
c. load
d. reliability
e. all of the above
46) what is the maximum allowable number of hops in enhanced interior routing gatewayprotocol? (在增强内部路由网关协议中，最多允许多少个跳计数)？
a. 64
b. 224
c. 128
d. 232
e. 256
47) enhanced interior routing gateway protocol uses which of the following (增强内部路由选择网关协议使用下列的哪一种)？
a. link-state vector
b. diffusion update algorithm
c. distance vector
d. a and b only
e. b and c only
a.5 第5章答案
1) d。在连接不相似的网络类型时要使用路由器。
2) a，d。组成路由选择协议的两个机制是选择最佳路由和传输数据。
3) c。路由选择表用来选择最佳路由。
4) a ，b，d。路由选择信息表包括目标网络地址和相关的数值，该数值提供了路由准则： 跳、代价度或者下一个路径。
5) c。路由选择更新是用来维护路由选择表的方法。
6) b，c。初始的数据包发送带有目标节点和m a c层(路由器的硬件地址)的网络地址的数据包。
7) a，c，d。路由选择协议的三个目标分别是：准确、快速收敛和低开销。
8) d。收敛在所有路由器的路由选择信息表同步时才发生。
9) b。因为路由在互连网络拓扑结构发生变化时将重新计算，所以动态路由协议是动态
10) a。静态路由是人工输入到路由选择表中并且从来不被路由选择协议更新的。
11) d。只有包含很少的路由器并且不经常改动的小网络适合于静态路由，这是因为静态路由在互连网络变动时要根据管理员的要求来更新每个路由器。
12) d。自治系统也可认为是一个区域或者域。它是在较大互连网络中定义的连续路由器集合；尽管它们共享路由选择信息，但是它们不向区域外传播信息。
13) d。默认路由通常是静态类型的路由，它可看作是最后求助的网关，在此所有非路由数据包进行转发以进一步处理。
14) b。因为距离向量路由器复制它们邻居的路由选择表，更新它们并且转发它们，所以它们使用了第二手信息。
15) a。无限计数问题是第二手信息产生的路由选择循环。
16) d。破坏逆转是水平分割的版本，它将“路由不可达”更新发送回路由器，从中可学习路由，这样可避免路由选择循环。
17) a。r i p是以前的距离向量协议和内部网关协议，它的更新周期是3 0秒，最多1 5个跳计数。
18) d。i g r p是一个距离向量和内部网关协议，最大网络直径是2 2 4 (即最多2 2 4个跳计数)。
19) c。瞬时更新用来加速收敛。
20) d。管理员可调整用于路由选择的加权值。
21) d。桥接、路由选择和交换都可以从一个网段向另一个网段移动通信量。
22) c。路由选择发生在网络层上。
附录a 自我测试题答案
23) c。度用来选择最佳路由。代价和距离在确定最佳路由中可以为一些路由算法用作度尺度。
24) a。路由器通常具有路径上目标节点的网络地址信息。
25) c。当接收到数据包时，路由器会检查目标节点的地址。如果路由器不能向目标地址发送数据包，那么路由器或者扔掉数据包，或者向默认路由器发送数据包。
26) b。开销通常和带宽及c p u使用相关。精度与优化的路由有关。
27) d。如果选择不变的网络拓扑结构为网络总体结构，那么收敛就不是一个问题。答案
a、b和c都表示变化的网络，它们都需要监视收敛。
28) b 。i p路由选择表允许路由器选择数据包要采用的下一步路由。
29) c 。ip route命令包括数据包使用的路由器接口的i p地址。它也包括路由指向的网络号和网络的子网掩码。
30) b。正确的命令是#ip route 86.0.0.0 255.0.0.0 35.3.3.4。答案a通过路由器x的接口向网络a路由通信量。答案c通过路由器x的接口向网络b路由信息量。答案d通过路由器y的接口向网络a路由流量。
31) b。错。要更改静态表，需要有授权者的参与。
32) c。在混合类型的网络中，非可路由数据包将路由到指定为最后求助的路由器的静态路由器中。
33) b。在故障的情况下，分布的路由选择协议提供了默认容错技术。
34) d。ip defa u lt命令需要一个网络号。
35) b。距离向量路由选择算法中的时效设置是针对所有的路由选择信息。
36) b。对于较大的或复杂的网络，如果停机周期足够长，那么就会尽可能地减少与网络稳定性有关的问题(尽管不是在所有情况下都适用)。
37) b。作为有关度，链接状态协议使用代价而不是路程段。
38) c。链接状态协议中的泛洪就是指链接状态路由器的邻居接收到有关链接状态数据包， 复制该数据包，然后将它转发到网络中的其余部分。
39) b. igp在网络内应用到自治系统。
40) a。外部网关协议就是域间协议，因为它们在域间运行。
41) b 。r i p有1 6个路程段的限制。
42) c 。r i p配置需要一个命令来启用r i p，还需要一个命令来激活r i p接口。
43) b 。r i p鉴别命令仅仅可以和r i p的第2版本一起使用。
44) d。在7个更新周期之后，将从路由选择表中删除路由。在i g r p中，每9 0秒更新一次广播。在三个更新周期之后，此时路由丢失，就是认为路由不可到达。7个周期之后，路由被删除。
45) e。在i g r p中，互连网络延迟、负载、带宽和可靠性都用来计算度值。
46) b 。e i g r p中用到的最大跳计数是2 2 4。
47) e。e i g r p将距离向量和d u a l一起使用，这改进了收敛属性。
篇2：题库精选:CCNA考试自测题第5卷
下面的问题将帮助你检查你对本章中材料的理解程度，仔细读下面的选项，可能有不止一个正确答案。选出每个问题中的正确答案。
1) match which of these protocols go with which access list range (匹配下列协议和访问列
表范围)？
a. novell sap ① 800~899
b. appleta l k ② 1000~1099
c. novell ③ 1~99
d. ip ④ 6 0 0 ~ 6 9 9
2) what happens to access lists previously created if the ios is upgraded from version 10.1 to 11.1 (如果i o s从1 0 . 1版升级到11 . 1版时，以前创建的访问列表会发生什么事情)？
a. they are dropped since they are no longer applicable
b. access lists didn’t exist prior to version 9.1
c. they will be converted to the new format
d. they will be left alone since ios 11.1 provides backward compatibility
3) in what ways are access lists typicallyimplemented on appletalk networks (在a p p l e ta l k网络中，通常访问列表是如何实现的)？
a. to control packets transmitted across an interface
b. to specify interesting traffic to launch a ddr connection
c. to restrict sap broadcasts
d. to advertise available servers
4) what do netware servers do to advertise their services and addresses to other servers ( n e t wa r e服务器如何对其他服务器通告其服务和地址)？
a. broadcast netbios packets
b. register with an sap server
c. broadcast sap packets
d. register with a netbios server
5) in the event of no matching rule being found in an ip access list, what happens to the transmission packet at the end (在i p访问列表中，如果到最后也没有找到匹配，则传输数据包将如何)？
a. it is dropped
b. it is allowed to pass
c. a broadcast is sent out notifying the sending host
d. a packet return (pr) is issued to the sending host
6) for which of the following reasons are ip-style appletalk access lists implemented (下列哪个是i p类型a p p l e ta l k访问列表实现的原因)？
a. for controlling the disposition of networks that overlap a network number range
b. for controlling the disposition of networks that are contained within a network number range
c. for controlling the disposition of networks that no longer exist within a network number range
d. for controlling the disposition of networks that exactly match a network number range
7) which of the following statements are true regarding ip access lists (考虑i p访问列表，下列哪个陈述是正确的)？
a. after an access list is created, any additions to that list are placed at the end
b. you can’t selectively add or remove items
c. you need to explicitly associate the access list to whatever it is you are intending to use it
f o r, such as an interface
d. there is an implicit deny statement at the end
8) on what basis do ipx access lists permit or deny traffic (ipx访问列表基于什么允许或拒绝通信量)？
a. specified network nodes
b. messages sent using a particular icmp
c. messages sent using a particular protocol
d. messages sent using a particular service
9) how often does a cisco router broadcast periodic sap advertisements (cisco路由器广播 s a p通告的周期是多长时间)？
a. as soon as it receives the complete packet
b. every 30 seconds
c. every 60 seconds
d. every 300 seconds (5 minutes)
10) what is gns (gns是什么)？
a. an icmp connectivity error packet
b. generic netware service (allows a cisco router to appear as a netware server)
c. appleta l k ’s default network routing algorithm
d. a packet sent out to request specific services from servers
11) which of the following are valid types of ipx access lists (下列哪个是有效的i p x访问列表类型)？
a. sap
b. netbios
c. icmp
d. extended
12) what are the two basic styles of appletalk lists (两种基本的a p p l e ta l k表样式是什么)？
a. appletalk style
b. macintosh style
c. nbp style
d. ip style
13) which of the following are true statements regarding phase 1 and phase 2 appleta l k networks (下面哪些是关于phase 1和phase 2 appleta l k网络的正确描述)？
a. phase 1 networks are more efficient at wan communication
b. phase 2 networks can have up to 255 zones
c. phase 1 networks can have only 1 zone
d. phase 2 networks introduced routing
14) how should you arrange your entries in appletalk access lists (你该如何安排a p p l e ta l k访问列表中的条目顺序)？
a. the order doesn’t matter
b. from the most specific to the most general
c. from the most general to the most specific
d. zones first, followed by systems
15) what will happen to packets that cross an interface where no access list has been defined(当数据包经过一个未定义访问列表的接口时会如何)？
a. they will be discarded
b. they will be allowed to pass through
c. they will be queued up
d. they will be returned to the sending host
16) which of the following examples follow the correct syntax for adding special macintosh characters in zone names (下列哪个例子正确表达了在区域名中加入特殊m a c i n t o s h字符的语法)？
a. /b2
b. -b2
c. [b2]
d. :b2
17) which of these are valid types of ip access lists (下列哪些是有效的i p访问列表类型)？
a. dynamic
b. dynamic extended
c. extended
d. standard
18) which of the following examples uses the correct syntax to define an appletalk access list for an extended or a non-extended network that is completely contained within a specificcable-range (下列哪些例子正确定义了a p p l e ta l k访问列表，既能为扩展网络也能为非扩展网络，且完全包括特定的电缆范围)？
a. access-list 599 permit within 100~150
b. access-list permit 225~240 within 699
c. access-list permit 225~240 within 599
d. access-list 699 permit within 100~150
19) which of the following statements regarding sap broadcasts is correct (考虑s a p广播， 下列哪个陈述是正确的)？
a. sap-type broadcasts do not work well across wans
b. each sap service is identified by an eight-digit binary number
c. because of sequencing issues, the times between sap table updates cannot be changed
d. sap stands for secondary addressing protocol
20) consider the following access list:
access-list 50 deny 136.120.3.1
access-list 50 deny 143.22.1.0 0.0.0.255
which statement represents the most complete description of the results of applying this list as a packet filter (考虑下述访问列表：
access-list 50 deny 136.120.3.1
access-list 50 deny 143.22.1.0 0.0.0.255
下列哪个陈述最完全地描述了访问列表作为数据包过滤的结果)？
a. it will deny all traffic destined for any host on network 136.120.3.0
b. it will deny all traffic destined for network 143.22.1.0
c. it will deny all traffic from the host at 136.120.3.1
d. it will deny all ip traff i c
21) which command would be used to configure a packet filter for ip traffic (下列哪个命令 可用来配置i p通信量的数据包过滤)？
a. router(config-if)#ip access-list 100
b. router(config-if)#ip access-group 42
c. router(config)#access-group 102
d. router(config-if)#access-group 75
e. router(config-if)#ip output-packet-filter 11 2
22) which command would be used to configure an inbound packet filter for tcp traffic (下 列哪个命令可用来配置t c p通信量的入站数据包过滤)？
a. router(config-if)#tcp pa c k e t- f i lter 101
b. router(config-if)#ip packet-filter 101 in
c. router(config-if)#ip access-group 99 in
d. router(config-if)#ip access-group 100 in
e. router(config-if)#ip access-group 100
23) the address mask pair 172.16.64.0 0.0.3.255 specifies which range of ip addresses (地址掩码对172.16.64.0 0.0.3.255指定了什么i p地址范围)？
a. 172.16.64.255 through 172.16.67.255
b. 172.16.67.0 through 172.16.70.255
c. 172.16.64.0 through 172.16.67.255
d. 172.16.63.0 through 172.16.64.255
24) the following statement appears in an ip extended access list:
access-list 125 permit ip any host 136.25.2.128
what does this line permit (下述是i p扩展访问列表中的语句：
access-list 125 permit ip any host 136.25.2.128
host 136.25.2.128
该行允许了什么)？
a. any ip traffic from host 136.25.2.128
b. ip traffic to any host on network 136.25.2.128
c. ip traffic from any address to the host at 136.25.2.128
d. the statement is invalid because there is no mask
25)the following access list, containing only one line, is applied as a packet filter on an interface.
access-list 100 permit tcp 145.22.3.0 0.0.0.255 any eq telnet
what is the best description of the traffic that is denied by the implicit deny all (下述访问列表，只有一行，用作一个接口的数据包过滤
access-list 100 permit tcp 145.22.3.0 0.0.0.255 any eq telnet
对于隐含的deny all，最合适的描述是什么)？
a. all ip traffic
b. all telnet traffic
c. all tcp traffic
d. all tcp traffic except te l n e t
篇3：题库精选:CCNA考试自测题第4卷
下面的问题将衡量你对本章内容的理解程度。仔细阅读所有的选项，因为可能有多个正确的选项。为每个问题选出正确的选项。
1) how long is an appletalk address (in bits) (appleta l k地址的位数为多长)？
a. 16 bits
b. 32 bits
c. 24 bits
d. 8 bits
2) what are the two parts of an appletalk address (appleta l k地址的两部分是什么)？
a. network and node
b. source and destination
c. logical and physical
d. standard and extended
3) which of the following is standard on almost all macintosh computers (下面哪一个选项是几乎所有的m a c i n t o s h计算机的标准)？
a. ethertalk
b. to k e n talk
c. fdditalk
d. localta l k
4) how many bits of an appletalk address are reserved for the node number (appleta l k地址为节点号保留了几位)？
a. 8 bits
b. 16 bits
c. 24 bits
d. 32 bits
5) network resources used by a particular group or department are grouped into what a p p l e talk structure (特定的组或部门使用的网络资源分组为什么a p p l e ta l k结构)？
a. workgroup
b. zone
c. cable range
d. virtual lan
6) what is the name of the appletalk layer-3 protocol (appleta l k第三层协议的名字是什么)？
a. datagram post office protocol
b. datagram delivery protocol
c. appletalk transport protocol
d. zone information protocol
7) which statement is true (下面哪句话是正确的)？
a. two zips can be assigned to an interface
b. two cable ranges can be assigned to an interface
c. two appletalk rtmps can be assigned to an interface
d. two zone names can be assigned to an interface
篇4：题库精选:CCNA考试自测题第3卷
下面的问题将帮助你评价你在本章中学习到的内容。仔细阅读所有的选项，因为正确答案可能多于1个。选择每个问题中所有的正确答案。
1) the service provided by ipx is (ipx提供的服务是)：
a. guaranteed delivery
b. datagram
c. connection-oriented
d. sequenced
2) the transport control field in the ipx header holds what information? (ipx报头中的传输 控制字段保留何种信息)？
a. the age of the packet.
b. protocol type
c. router hop count
d. level of service required.
3) what is the length of an ipx network number (ipx网络编号的长度是多少)？
a. 16 bits
b. variable
c. 48 bits
d. 32 bits
4) in the ipx address 0102.0000.8045.1700, what is the node address ( 在i p x地址 0 1 0 2 . 0 0 0 . 8 0 4 5 . 1 7 0 0中，节点地址是多少)？
a. 1700
b. 0102.0000.8045
c. 0102.0000
d. 0000.8045.1700
5) what can you say about this address: 47.0000.0000.0001 (关于这个地址 4 7 . 0 0 0 0 . 0 0 0 0 . 0 0 0 1，你可以说)：
a. it is the address of a netware print server
b. it is an internal network address
c. the included socket number is 0001
d. nothing
6) the checksum field in the ipx header is normally set to (ipx报头中的校验和字段通常设置为)：
a. a checksum of the entire ipx packet
b. a checksum of the ipx header fields only
c. 0xffff
d. 0
7) if an ipx node is configured to use the ethernet_802.2 encapsulation, which other machines can it communicate with directly (without going through a router) on the same network (如果一个i p x节点配置为使用e t h e r n e t _ 8 0 2 . 3封装，它可以和相同网络上其他哪一个设备直接通信(不经过路由器) )？
a. machines running any encapsulation
b. machines running either ethernet_802.2 or ethernet_802.3
c. machines running ethernet_ii
d. machines running ethernet_802.2
8) to run multiple encapsulations on a single physical interface, a router has to (为在一个物理接口上运行多个封装，路由器必须)：
a. use a different network number for each encapsulation
b. use subinterfaces, not secondary networks
c. enable nlsp routing
d. use an access list
9) which protocol does a workstation use to locate a server providing a particular type of service (工作站使用哪一个协议来找到提供特定类型服务的服务器)？
a. rip
b. ncp
c. sap
d. eigrp
10) periodic sap updates are sent by (定期s a p更新由谁发出)：
a. routers and servers
b. netware servers only
c. workstations and routers
d. workstations only
11) the rip protocol is used by (rip协议由谁使用)？
a. routers only
b. servers only
c. workstations, servers, and routers
d. print servers
12) which command which must be given first to enable ipx (在启用i p x时，必须首先给出哪一个命令)？
a. cisco(config)#enable ipx routing
b. cisco>ipx routing
c. cisco(config-if)#ipx routing on
d. cisco(config)#ipx routing
13) which of the following allow you to use multiple ipx networks on a single physical interface (下面哪一个允许你在单个物理接口上使用多个i p x网络)？
a. secondary networks
b. dynamic frame types
c. subinterfaces
d. none. this is not supported.
14) which ios command allows you to view the router’s internal sap database (哪一个i o s 命令允许你查看路由器的内部s a p数据库)？
a. show serv e r s
b. show ipx servers
c. servers
d. ipx servers
15) which of the following kinds of information do you need to collect before you can configure ipx using ios (你需要在用i o s配置i p x之前搜集下面各种信息中的哪一个)？
a. the number of netware servers on the network
b. the encapsulations in use
c. ipx network numbers
d. the ipx address of another router
16) what does this command do:
cisco(config-if)#ipx network 3 (这个命令的作用是什么： c i s c o ( c o n f i g -
if)#ipx network3)：
a. nothing. it is incomplete.
b. sets up a static route to network 3
c. configures ipx network 3 on this interface with the default frame type
d. nothing. the router is in the wrong configuration mode.
17) what does this ios command do?
ipx route 4 5.0000.8004.4563 float i n g - s tatic (这个i o s命令的作用是什么i p x route 45.0000.8004.4563 float i n g - s tat i c )？
a. configures 4 static routes
b. configures static sap entries for servers of type 4
c. configures a static route to network 4
d. says that to get to network 5, you must go via network 4
18) in the command ipx route 4 5.0000.8004.4563 float i n g - s tatic, what does the f l o at i n g - s tatic keyword on the end mean? ( 在命令ipx route 45.0000.8004.4563
f l o at i n g.s tat i c中，最后的f l o at i n g.s tat i c意味着什么)？
a. set all static routes to floating
b. allow this route to be overridden by a route received dynamically
c. apply this route to all network numbers from 1 to 4
d. lock this route so that it cannot be changed
19) the ipx maximum-paths command does what (ipx maximum.pat h s命令的作用是什么)？
a. allows ios to share traffic to a given network over multiple paths
b. allows a slow link to be used as a backup for a faster one
c. sets the maximum number of router hops a packet can travel
d. sets the maximum number of interfaces ipx can be configured on
20) which command is used to show a concise list of the configured ipx interfaces (哪一个命令用于显示配置的i p x接口上的简明列表)？
a. show config
b. show ipx interface
c. show ipx interface brief
d. show interface
21) if two devices are plugged into the same physical network, but are using diff e r e n t encapsulations, what it required before they can communicate (如果在相同的物理网络中加入了两个设备，但是使用不同的封装，在它们通信之前需要完成什么)？
a. a cross-over cable
b. a repeater
c. a router configured for the appropriate encapsulations
d. nothing. they can communicate directly.
22) when does a workstation normally send a gns request (工作站一般在什么时候发出g n s请求)？
a. when trying to communicate with another workstation
b. when trying to locate the nearest router
c. when it needs to send a sap update
d. when trying to locate a server at initialization
23) how many router hops does a gns request travel (一个g n s请求经过多少个路由器跳)？
a. 16
b. none
c. 4
d. unlimited
24) in a sap update packet, what does the server address field contain (在s a p更新数据包中，服务器地址字段中包含什么)？
a. the network the server is on
b. the server’s node number
c. the socket number the server is listening on
d. all of the above.
25) which of the following protocols is used by servers to advertise their services to the clients (下面协议中的哪一个由服务器使用，以向客户通告它们的服务)？
a. routing information protocol (rip)
b. sequenced packet exchange (spx)
c. network core protocol (ncp)
d. service advertising protocol (sap)
26) on an ethernet lan how many ipx encapsulation types are supported (在一个e t h e r n e t局域网上，可以支持多少个i p x封装)？
a. 4
b. 3
c. 2
d. 1
27) the frame check sequence checks with which fields in an ethernet_802.3 frame (帧校验序列校验e t h e r n e t - 8 0 2 . 3帧中的哪一个字段)？
a. the source address and destination addres
b. the packet data
c. everything from the destination address on
d. source service access point (ssap)
28) which of the following fields is not common to both ethernet_802.3 and ethernet_802.2 frames (下面字段中的哪一个不是e t h e r e n e t 8 0 2 . 3和e t h e r n e t 8 0 2 . 3帧所共有的)？
a. source address
b. length
c. dsap
d. data
29) in sap packets, the numbers in the service type field are assigned by (在一个s a p数据包中，服务类型字段中的数字由谁给定)？
a. the system administrator
b. the end user
c. novell
d. server
30) sap requests, responses, or broadcasts can be recognized by which value of source or destination socket number (sap请求，响应或广播可以通过源或目的套接字数字中的哪一个值来识别)？
a. 0x0452
b. 0xe0
c. 0x03
d. 0x0453
31) in rip packets, the hops away and time ticks fields are valid both for request and response packets (在r i p数据包中，“跳距离”和“时间嘀嗒数”字段对于请求和响应数据包都是合法的)。
a. true
b. false
32) up to how many rip entriescan a single ipx packet hold (一个i p x数据包可以保留多少个r i p条目)？
a. 44
b. 47
c. 49
d. 51
33) in rip, which number of hop counts indicates that a network is unreachable (在r i p中，多少个跳距离表示无法达到一个网络)？
a. 12
b. 16
c. 8
d. 20
34) match a novell term on the left with an ios term on the right (匹配左边的n o v e l l术语和右边的i o s术语)。
a. ethernet_snap 1. sap
b. ethernet_802.2 2. snap
c. ethernet_ii 3. novell-ether
d. ethernet_802.3 4. arpa
35) if a user attempts to set the same encapsulation type on more than one subinterface on the same physical interface, what will the ios do (如果一个用户企图在相同物理接口的多个子接口上设置相同的封装类型， i o s将给出什么结果)？
a. assign default values for encapsulation types
b. issue a warning but allow the change
c. issue an error message and ignore the change
d. allow the change
36) which of the following is a default routing protocol when ipx routing is enabled (下面的哪一个是启用i p x路由时的默认路由协议)？
a. rip
b. nlsp
c. eigrp
d. cdp
37) when there are multiple paths available at the same cost, then by default ios: (当存在代价相同的多个路径时，在默认情况下)：
a. will keep all paths in the routing table
b. will keep only one path in the routing table
c. will keep all paths in the table and route the traffic in a round-robin manner
d. b and c
38) what is the purpose of the split-horizon function (水平分割的目的是什么)？
a. to divide the network traffic in two for faster throughput
b. to avoid sending redundant data back out the interface it was received on
c. so that each person only has to manage half the routers on a network
d. to set traffic priority levels
39) by default, rip routers broadcast periodic updates every (默认情况下，r i p路由器每隔多长时间进行广播)？
a. 30 seconds
b. 60 seconds
c. 5 minutes
d. 10 minutes
40) when would a workstation send a rip request (何时一个工作站会发送r i p请求)？
a. on initialization, to locate a server
b. whenever it needs to find a route to a remote network it doesn’t have a route for
c. to connect to a netware server
d. every 60 seconds
41) if an interface was configured like this:
c i s c o ( c o n f i g ) # i n t e r face ethernet 1
cisco(config-if)#ipx network 201 encapsulation novell-ether
cisco(config-if)#ipx network 202encapsulation sap secondary
how many copies of each sap update would be sent out the physical interface (如果一个接口这样配置：
c i s c o ( c o n f i g ) # i n t e r fa c e
e t h e r n e t 1
cisco(config-if)#ipx network
201 encapsulat i o n
n o v e l l - e t h e r
cisco(config-if)#ipx network
202 encapsulation sap
s e c o n d a ry
则在物理接口上可以发出s a p更新的多少个副本)
a. 1
b. 2
c. 3
d. 4
a.7 第7章答案
1) b。i p x仅仅提供了不可靠的、无连接数据报服务。
2) c。i p x报头中的传输控制字段控制路由器跳计数信息。当数据包生成时，传输控制字段初始化为0，并且在它每次通过路由器时都增加。
3) d。尽管通常网络号开头的0都省略掉，但是网络号是一个长度为3 2的数字。
4) d。节点地址是0 0 0 0 . 8 0 4 5 . 1 7 0 0。i p x地址总是以网络号开始，然后是节点地址。有时再加上套接字号。
5) b。它是一个内部网络地址。服务器总是内部网络上的节点0 0 0 0 . 0 0 0 0 . 0 0 0 1。
6) c 。默认情况下不使用i p x报头中的校验和字段。生成数据包时，该字段设置为0 x f f f f。
7) d。要直接通信，节点必须运行相同的帧类型。
8) a。接口上使用的每个封装组成了它自己的i p x网络，所以必须给它网络号。每个网络号必须是i p x互连网络上唯一的编号。
9) c。工作站使用服务通告协议( s a p )来定位提供特殊服务类型的服务器。
10) a。路由器和服务器定期发送s a p更新。所有服务器使用广播通告可用的服务。路由器记录这些通告，并且将通告作为s a p数据库的一部分来重新通告。工作站仅仅广播g n s查询，它从来不传输更新。
11) a.工作站、服务器和路由器都使用r i p在远程网络中定位路由。
12) d。首先执行命令ipx routing来启用i p x。尽管答案b有正确的命令，但是路由器是以错误的模式接受的。
13) a，c。次级网络和子接口都允许用户在物理接口上有多个i p x网络。不过，接口上的每个网络必须在不同的封装上运行。
14) b 。命令show ipx serv e r s允许用户查看路由器的内部s a p数据库。此时将显示s a p表的内容。
15) b ，c。如果要在安装中避免问题，那么使用的封装和i p x网络号是必要的。
16) c。因为没有指定封装，所以该接口使用默认介质类型。
17) c。配置到网络4的静态路由。5 . 0 0 0 0 . 8 0 0 4 . 4 5 6 3是到网络4的下一跳的路由器。
18) b。末端的关键字f l o at i n g - s tat i c含义是，如果r i p通告的路由或者网络4接收另一个路由选择协议，那么它将优先于静态路由。如果不是这样，那么该网络进入的动态路由将要忽略掉。
19) a。命令ipx maximum-pat h s允许到给定网络的多个路径。路径必须具有相同的代价。默认情况下， i o s仅仅有一条通向每个目标网络的路径。
20) c 。命令show ipx interface brief显示了所配置的i p x接口的简明列表。尽管答案b显示了列表，但是它并不是简明的。
21) c。如果它们没有运行相同的封装， 那么路由器是唯一可以和它们连接的设备。
22) d。当工作站首先出现时，它需要查找要连接的n e t wa r e服务器。一旦连接成功，它就可以使用服务器数据库来定位服务器。
23) b。g n s请求是一个广播。默认情况下，路由器阻塞这些广播，所以它们仅仅在本地网络中可见。
24) d 。s a p更新包括带有服务器套接字号的完整的互连网络地址。
25) d。s a p通告是通告服务信息的服务器所发出的广播。
26) a。ethernet lan支持的i p x封装的四种类型分别是： e t h e r n e t _ i i，e t h e r n e t _ 8 0 2 . 2，
e t h e r n e t _ 8 0 2 . 3和e t h e r n e t _ s n a p。
27) c 。f c s用来检测破坏的数据包，并且检查所有的i p x数据包字段。
28) c 。d s a p字段在e t h e r n e t _ 8 0 2 . 2帧中，它不是在e t h e r n e t _ 8 0 2 . 3帧中。
29) c 。“服务类型”字段包括n o v e l l分配的号。
30) a 。s a p请求、响应或者广播可以为0 x 0 4 5 2的源和目标套接字号所识别。d s a p和s s a p字段中的e t h e r n e t _ 8 0 2 . 2版使用0 x e 0。0 x 0 3是e t h e r n e t _ 8 0 2 . 2帧中的控制位组的数值。 0 x 0 4 5 3用作r i p帧中的套接字号。
31) b。错误。在r i p请求中，两个字段都包括数值0 x f f f f。在响应数据包中，它们包括合法的数值。
32) c 。单个i p x数据包可以控制至多4 9个r i p条目。
33) b 。在r i p中，1 6的路程段数说明网络是不可达的。
34) a-2，b - 1，c - 4，d - 3。这些对应在表7 - 1中列出。
35) c。如果用户试图在相同物理接口上的多个子接口上设置相同的封装类型，那么i o s将发出错误信息并且忽略改动。
36) a 。在i p x启用时，r i p是默认的路由选择协议。
37) b。默认情况下， i o s仅仅使用通向每个网络的最佳路径，并且沿该路径发送所有的通信量。
38) b。水平分割的用途是避免冗余。没有将s a p条目发送回最初接收它们的网段中，该网段的通信信息量减少，并且避免了混乱的循环。
39) b。默认情况下，每隔6 0秒发送一次r i p更新。
40) b。工作站使用r i p定位远程网络中的路由。
41) b。发送每个s a p更新的两个副本：一个发送到n o v e l l - e t h e r封装的网络2 0 1，另一个发送到s a p封装上的网络2 0 2。
篇5：题库精选:CCNA考试自测题第1卷
下面的问题将帮助你评价你在本章中学习到的内容。仔细阅读所有的选项，因为正确答案可能多于1个。选择每个问题中所有的正确答案。
1) match the following application layer services to their corresponding transport layer protocol port. (匹配下列的应用层服务和它们对应的传输层协议端口)：
a. smtp 1. tcp/23
b. ftp 2. tcp/25
c. tftp 3. tcp/80
d. te l n e t 4. tcp/21
e. http 5. udp/69
f. dns 6. tcp/53
2) which osi reference model layer does telnet function at (te l n e t在哪一个o s i参考模型层运作)？
a. transport
b. network
c. session
d. application
3) how many layers does the tcp/ip protocol suite have, compared to the osi reference model (和o s i参考模型相比，t c p / i p协议具有几层)？
a. tcp model has 4, osi model has 6
b. tcp model has 7, osi model has 8
c. tcp model has 4, osi model has 7
d. tcp model has 7, osi model has 4
4) the tcp/ip protocol suite has a formal session layer that includes netbios、rpcs and tli functions (tcp/ip协议套件具有包含n e t b i o s、r p c和t l i功能的一个正式的会话层)。
a. true
b. false
5) what is the function of rpcs (rpc的功能是什么)？
a. to move files from remote pcs to a local pc
b. to make remote function calls transparent, so they appear to be local
c. to initialize a program on a remote pc
d. to send a procedure that is local to a remote node for processing elsewhere
6) what does rpc stand for (rpc代表什么)？
a. remote personal computer
b. reserved-programming call
c. routed-procedure call
d. remote-procedure call
7) what osi reference model layer do sockets function at (套接字在o s i参考模型的哪层运作)？
a. application
b. presentation
c. session
d. transport
e. network
f. data link
g. physical
8) what function do sockets perform (套接字的功能是什么)？
a. they make remote functions appear local, transparent to the user
b. they transfer files to and from remote nodes
c. they make the transport layer independent
d. they allow multiple applications to share the same connection to the network
9) what is winsock (什么是wi n s o c k )？
a. a version of sockets for the microsoft windows platform
b. sockets on bsd unix
c. a session layer api commonly considered to be its own protocol
d. a network layer service for microsoft wi n d o w s
10) what does tli do (tli的作用是什么)？
a. it makes remote functions appear local, transparent to the user
b. it transfers files to and from remote nodes
c. it makes the transport layer independent
d. it allows multiple applications to share the same connection to the network
11) what osi layer does netbios function at (netbios在o s i哪一层运作)？
a. application
b. presentation
c. session
d. transport
e. network
f. data link
g. physical
12) which protocols can netbios bind to? (select all that are applicable.) (netbios可以绑定在哪个协议上，选择所有可能的协议)？
a. appletalk
b. ipx
c. ip
d. netbeui
13) what layers do not exist in the tcp/ip model that are in the osi model (哪层不在t c p / i p模型中，但它在o s i模型中)？
a. application, presentation, and network
b. presentation, session, and data link
c. session, network, and physical
d. presentation, data link, and physical
14) what is a socket in the transport layer (传输层中的套接字是什么)？
a. the socket is an ip address plus a port
b. an api that makes the transport layer independent
c. an api that allows multiple applications to share a network connection
d. a function that makes remote procedures appear to be local
15) what is a port (什么是端口)？
a. an api that makes the transport layer independent
b. an api that allows multiple applications to share a network connection
c. a function that makes remote procedures appear to be local
d. the point where upper-layer processes access transport layer services
16) which of the following services uses a process called windowing (下面的哪一个服务使用了所谓的窗口机制)？
a. reliable data transfer
b. connection-oriented virtual circuit
c. buffered transfer
d. resequencing
e. multiplexing
f. efficient, full-duplex transmission
g. flow control
17) what is udp (什么是u d p )？
a. an api that makes the transport layer independent
b. a connectionless, unreliable transport protocol
c. an api that allows multiple applications to share a network connection
d. a function that makes remote procedures appear to be local
18) what is ip (什么是i p )？
a. it is the transport mechanism for upper layer services
b. it is the session layer api for making the transport layer independent
c. it is the network layer protocol that moves data from one node to another
d. it is the physical layer protocol for internet connections
19) what is icmp (什么是i c m p )？
a. it is a network layer protocol that handles control messages
b. it is a network layer protocol that resolves addresses
c. it is a session layer api that makes remote procedures transparent to a user
d. it is a transport layer function for unreliable transport
20) ping sends an icmp echo command to an ip address in order to determine whether anetwork connection exists to that node (ping向一个i p地址发送了一个i c m p回送命令，目的是确定是否存在到那个节点的网络连接)？
a. true
b. false
21) which of the following best describes tcp/ip (下面的哪句话最准确地说明了t c p / i p )？
a. a static protocol
b. a proprietary protocol
c. a collection of internetworking protocols
22) udp and tcp represent mechanisms used by which layer of the tcp/ip (udp和t c p表示了t c p / i p的哪层使用的机制)？
a. data link layer
b. physical layer
c. presentation layer
d. transport layer
23) rpcs provide which of the following (rpc提供了下面的哪个功能)？
a. connection-oriented session
b. transparency to make remote calls look local
c. portability of applications between heterogeneous systems
d. a and c only
e. b and c only
f. a, b, and c
24) distributed computing environment (dce) is an example of (分布式计算环境( d e c )是下面的哪一项的一个例子)？
a. osi model
b. rpc implementation
c. extreme data representation
d. a and b
25) which statement is true of winsock (下面对wi n s o c k的哪一句陈述是正确的)？
a. it is a mac application
b. it represents a graphical user interface
c. it represents a network layer
d. it provides the means for sharing an internet connection between multiple ip protocol suite utilities
26) which statement is true of tli (下面关于t l i的哪一句陈述是正确的)？
a. it is a layer in the osi model
b. it is a layer in the tcp/ip model
c. it is a system v api
d. it is part of the unix kernel
27) which statement is true of windows name server (wins) (下面对于windows 命名服务器( w i n s )的陈述中，哪一句是正确的)？
a. it is a protocol
b. it provides capability for name resolution
c. it is a network layer
d. it is a proprietary name server
e. a, b, and d only
f. b and d only
28) icmp、i p、arp and rarp of the ip protocol suite map to (ip协议套件的i c m p、i p、a r p和r a r p映射到)：
a. osi layers 1 and 2
b. osi layer 5
c. osi layer 3
d. osi layer 2
29) which layer is most important in providing reliable data exchange between two systems(在两个系统之间提供可靠的数据交换中，哪一层是最重要的)？
a. physical layer
b. data link layer
c. session layer
d. transport layer
30) which of the following does tcp provide (tcp提供了下面的哪一个功能)？
a. unreliable data stream
b. connectionless virtual circuit
c. flow control
d. structured byte stream movement
31) of the following, which field is not a part of the tcp header (在下面各项中，哪一个字段不是t c p报头的一部分)？
a. subnet mask
b. sequence number
c. data offset
d. destination port
32) what is the sequence number in a tcp header used for (在t c p报头中的顺序号的作用是什么)？
a. acknowledgments
b. reordering of the octets received
c. rejecting duplicate octets
d. all of the above
33) variable sliding windows provide an explicit mechanism for notifying tcp if an intermediate node (for example, a router) becomes congested (在中间节点，例如一个路由器拥塞的情况下，可变滑动窗口提供了通知t c p的显式机制)。
a. true
b. false
34) which of the following parameters is not a part of udp header (下面的哪一个参数不是u d p报头的一部分)？
a. source port
b. urgent pointer
c. checksum
d. length
e. destination port
35) when a router has been configured for udp flooding, the source address might change,but the destination address will not change as the datagram propagates through the network (当一个路由器已经配置为u d p泛洪时，当数据报在网络上传播的过程中，源地址可能改变，但是目的地址不会改变)？
a. true
b. false
36) the spanning-tree algorithm allows (生成树算法允许)：
a. forwarding of packets with no control
b. forwarding of broadcasts to an interface which already has received the broadcast
c. prevention of duplication of forwarding of packets
d. a and b only
37) ip helper addresses are a form of _ _ _ _ _ _ _ _ _ _ _ _ _ _ addressing and require the command specification of _ _ _ _ _ _ _ _ _on every interface receiving broadcasts that need to be forwarded (ip辅助地址是一种什么类型的寻址方法，在每一个接收到需要转发的广播接口上需要什么命令说明)？
a. static / ip header address
b. dynamic / ip forward-protocol udp
c. dynamic / ip forward-protocol tcp
38) which of the following protocols provide address resolution (下面的哪一个协议提供了地址解析)？
a. icmp
b. rarp
c. ip
d. udp
e. tcp
39) ip is described as an unreliable mechanism because it does not guarantee delivery (ip被认为是不可靠的机制，因为它不保证发送)。
a. true
b. false
40) what does fragmentation in tcp/ip represent (在t c p / i p中的分段代表什么)？
a. segmenting of datagrams into 53-byte packets for atm applications
b. division of larger datagrams into convenient size packets
c. a process that occurs on a router
d. a, b, and c
e. a and c only
f. b and c only
41) which of the following statements is true of arp (下面对a r p的陈述中，哪一个是正确的)？
a. it makes a mac address logically independent of the physical hardware
b. it makes it necessary for the administrator to physically manage the mac address of each n i c
c. it integrates routing function with the physical and data link layers
d. it routes packets based on destination host, not on destination network
42) a host’s arp cache is good forever once it has been created (一个主机的a r p高速缓存 一旦创建，则它永远工作良好)。
a. true
b. false
43) arp is a broadcast protocol, and arp caching is used because broadcasts are expensive ( a r p是一个广播协议，并且使用了a r p高速缓存，原因是广播太昂贵了)。
a. true
b. false
44) reverse address resolution protocol (rarp) is termed“r e v e r s e”because (反向地址解析协议( r a r p )中的“反向”的含义是)：
a. it is used by the system that knows its ip address but does not know its mac address
b. it is used by the system that knows its mac address but does not know its ip address
c. it is used by the system that knows the destination’s ip address but does not know the d e s t i n a t i o n ’s mac address
d. it is used by the system that knows the destination’s mac address but does not know the d e s t i n a t i o n ’s ip address
45) inverse address resolution protocol (inarp) is generally used by (逆向地址解析协议( i n a r p )通常由什么使用)？
a. broadcast networks
b. nonbroadcast networks
c. both broadcast and nonbroadcast networks
46) the ping command makes use of what icmp parameter (ping命令使用了什么i c m p参数)？
a. redirect
b. source quench
c. echo reply
d. destination unreachable
47) icmp redirect is sent by (icmp重定向由什么发出)？
a. a host to the gateway
b. a gateway to the host
c. a router to another router
d. a router to a network
a.4 第4章答案
1) a-2，b - 4，c - 5，d - 1，e - 3，f - 6
2) d。te l n e t是应用层服务。
3) c。t c p / i p协议套有四层，o s i参考模型有7层。
4) b。错。t c p / i p协议套没有正式的会话层。
5) b。r p c的功能是透明访问远程过程，使得它们作为本地的过程出现。
6) d。r p c是远程过程调用的缩写。
7) c。套接字在会话层运行。
8) d。套接字允许多个应用程序使用相同的t c p / i p连接。
9) a。wi n s o c k是套接字的microsoft wi n d o w s版本。
10) c。传输层接口使得传输层和上层服务相互无关。
11) c。n e t b i o s在o s i模型的会话层上运作。
12) b ，c，d。n e t b i o s可用在i p x、i p和n e t b e u i上运行。
13) b 。t c p / i p模式中没有正式的表示层、会话层和数据链路层。
14) a。套接字就是一个i p地址加一个端口。
15) d。端口就是上层进程访问传输层的位置。
16) g。窗口技术是一个流控制的格式。
17) b 。u d p是一个无连接的、不可靠的传输协议。
18) c 。ip(internet protocol)就是从一个节点向另一个节点传输数据的网络层协议。
19) a 。i c m p在网络层上处理控制消息。
20) a 。正确。p i n g向i p地址发送i c m p回送命令，验证可从本地主机到达这个地址。
21) c 。t c p / i p是动态改变的互连网络协议的集合。
22) d 。t c p和u d p表示了t c p / i p协议结构中的传输机制。
23) e。r p c为远程调用看上去像本地调用提供了透明性，而且还提供了异种系统间应用程序的移植性。r p c是一个连接会话。
24) b 。d c e是一个r p c工具。
25) d。wi n s o c k表示了会话层a p i允许多个应用程序共享一个internet 连接。它不是g u i。
26) c 。t l i表示system v应用程序编程接口。
27) f。w i n s是m i c r o s o f t专有n e t b i o s命名服务器，该服务器提供了名称解析的功能。
28) c 。i c m p、i p、a r p和r a r p都映射到o s i第3层。
29) d。不管t c p / i p协议套件之间的基础网络如何，传输层是确定可靠数据传输的最重要的层。
30) c。t c p提供了带有可靠位组流的面向连接的虚电路，在此，位组流是连续的和非结构化的。
31) a。子网掩码不是t c p报头的一部分。
32) d。t c p报头中的顺序号用来确认，也用来记录接收的8位位组以及拒绝重复的8位位组。
33) b 。错。
34) b。紧急( u rg e n t )指针不是u d p报头的一部分。u d p报头有四个参数：源端口、目标端口、长度和u d p校验和。
35) b。错。目标地址可能改变，但是源地址不能改变。
36) c。生成树以可控制的方式转发数据包。
37) a。i p辅助地址是静态寻址的格式，并且，它在每个接口需要转发的广播的接口上，需要i p报头地址的规范。
38) b 。r a r p是反向地址解析协议。
3 9 ) a。正确。i p被视为不可靠的机制，因为它没有保证递送。
40) f。分段是发生在源和目标之间路由器上的进程。该进程将数据报分解为适合于网络传输的单个帧的适当尺寸。
41) a。使用a r p，管理员不必实际管理每个n i c的m a c地址。a r p从物理层和数据链路层中分离出路由选择功能。a r p在目标网络上路由数据包，而不是在目标主机上。
42) b。错。主机的a r p缓存仅仅适用于确定的时间周期，然后它会超时。
43) a。正确。a r p是广播协议，并且因为广播的代价很高，所以使用a r p缓存。
44) b 。系统使用r a r p来解析i p地址。
45) b。逆向地址解析协议( i n a r p )通常由帧中继这样的非广播网络使用。
46) c 。p i n g命令使用回送请求和回送应答参数。
47) b 。i c m p重定向通过网关发送到主机。在路由器检测它的路由没有另一个路由器的路由优化时，它指令主机使用不同的路由。
篇6：CISCO模拟试题:CCNA考试自测题2
25) which statement is true of winsock (下面对wi n s o c k的哪一句陈述是正确的)？
a. it is a mac application
b. it represents a graphical user interface
c. it represents a network layer
d. it provides the means for sharing an internet connection between multiple ip protocol suite utilities
26) which statement is true of tli (下面关于t l i的哪一句陈述是正确的)？
a. it is a layer in the osi model
b. it is a layer in the tcp/ip model
c. it is a system v api
d. it is part of the unix kernel
27) which statement is true of windows name server (wins) (下面对于windows 命名服务器( w i n s )的陈述中，哪一句是正确的)？
a. it is a protocol
b. it provides capability for name resolution
c. it is a network layer
d. it is a proprietary name server
e. a, b, and d only
f. b and d only
28) icmp、i p、arp and rarp of the ip protocol suite map to (ip协议套件的i c m p、i p、a r p和r a r p映射到)：
a. osi layers 1 and 2 b. osi layer 5
c. osi layer 3 d. osi layer 2
29) which layer is most important in providing reliable data exchange between two systems (在两个系统之间提供可靠的数据交换中，哪一层是最重要的)？
a. physical layer b. data link layer
c. session layer d. transport layer
30) which of the following does tcp provide (tcp提供了下面的哪一个功能)？
a. unreliable data stream
b. connectionless virtual circuit
c. flow control
d. structured byte stream movement
31) of the following, which field is not a part of the tcp header (在下面各项中，哪一个字
段不是t c p报头的一部分)？
a. subnet mask b. sequence number
c. data offset d. destination port
32) what is the sequence number in a tcp header used for (在t c p报头中的顺序号的作用是什么)？
a. acknowledgments
b. reordering of the octets received
c. rejecting duplicate octets
33) variable sliding windows provide an explicit mechanism for notifying tcp if an intermediate node (for example, a router) becomes congested (在中间节点，例如一个路由器拥塞的情况下，可变滑动窗口提供了通知t c p的显式机制)。
a. true b. false
34) which of the following parameters is not a part of udp header (下面的哪一个参数不是u d p报头的一部分)？
a. source port b. urgent pointer
c. checksum d. length e. destination port
35) when a router has been configured for udp flooding, the source address might change,but the destination address will not change as the datagram propagates through the network (当一个路由器已经配置为u d p泛洪时，当数据报在网络上传播的过程中，源地址可能改变，但是目的地址不会改变)？
a. true b. false
36) the spanning-tree algorithm allows (生成树算法允许)：
a. forwarding of packets with no control
b. forwarding of broadcasts to an interface which already has received the broadcast
c. prevention of duplication of forwarding of packets
d. a and b only
37) ip helper addresses are a form of _ _ _ _ _ _ _ _ _ _ _ _ _ _ addressing and require the command specification of _ _ _ _ _ _ _ _ _on every interface receiving broadcasts that need to be forwarded (ip辅助地址是一种什么类型的寻址方法，在每一个接收到需要转发的广播接口上需要什么命令说明)？
a. static / ip header address
b. dynamic / ip forward-protocol udp
c. dynamic / ip forward-protocol tcp
38) which of the following protocols provide address resolution (下面的哪一个协议提供了地址解析)？
a. icmp b. rarp c. ip
d. udp e. tcp
39) ip is described as an unreliable mechanism because it does not guarantee delivery (ip被认为是不可靠的机制，因为它不保证发送)。
a. true b. false
40) what does fragmentation in tcp/ip represent (在t c p / i p中的分段代表什么)？
a. segmenting of datagrams into 53-byte packets for atm applications
b. division of larger datagrams into convenient size packets
c. a process that occurs on a router
d. a, b, and c
e. a and c only
f. b and c only
41) which of the following statements is true of arp (下面对a r p的陈述中，哪一个是正确的)？
a. it makes a mac address logically independent of the physical hardware
b. it makes it necessary for the administrator to physically manage the mac address of each n i c
c. it integrates routing function with the physical and data link layers
d. it routes packets based on destination host, not on destination network
42) a host’s arp cache is good forever once it has been created (一个主机的a r p高速缓存一旦创建，则它永远工作良好)。
a. true b. false
43) arp is a broadcast protocol, and arp caching is used because broadcasts are expensive ( a r p是一个广播协议，并且使用了a r p高速缓存，原因是广播太昂贵了)。
a. true b. false
44) reverse address resolution protocol (rarp) is termed“r e v e r s e”because (反向地址解析协议( r a r p )中的“反向”的含义是)：
a. it is used by the system that knows its ip address but does not know its mac address
b. it is used by the system that knows its mac address but does not know its ip address
c. it is used by the system that knows the destination’s ip address but does not know the destination's mac address
d. it is used by the system that knows the destination’s mac address but does not know the destination's ip address
45) inverse address resolution protocol (inarp) is generally used by (逆向地址解析协议( i n a r p )通常由什么使用)？
a. broadcast networks
b. nonbroadcast networks
c. both broadcast and nonbroadcast networks
46) the ping command makes use of what icmp parameter (ping命令使用了什么i c m p参数)？
a. redirect b. source quench
c. echo reply d. destination unreachable
47) icmp redirect is sent by (icmp重定向由什么发出)？
a. a host to the gateway
b. a gateway to the host
c. a router to another router
d. a router to a network
25) which statement is true of winsock (下面对wi n s o c k的哪一句陈述是正确的)？
a. it is a mac application
b. it represents a graphical user interface
c. it represents a network layer
d. it provides the means for sharing an internet connection between multiple ip protocol suite utilities
26) which statement is true of tli (下面关于t l i的哪一句陈述是正确的)？
a. it is a layer in the osi model
b. it is a layer in the tcp/ip model
c. it is a system v api
d. it is part of the unix kernel
27) which statement is true of windows name server (wins) (下面对于windows 命名服务器( w i n s )的陈述中，哪一句是正确的)？
a. it is a protocol
b. it provides capability for name resolution
c. it is a network layer
d. it is a proprietary name server
e. a, b, and d only
f. b and d only
28) icmp、i p、arp and rarp of the ip protocol suite map to (ip协议套件的i c m p、i p、a r p和r a r p映射到)：
a. osi layers 1 and 2 b. osi layer 5
c. osi layer 3 d. osi layer 2
29) which layer is most important in providing reliable data exchange between two systems (在两个系统之间提供可靠的数据交换中，哪一层是最重要的)？
a. physical layer b. data link layer
c. session layer d. transport layer
30) which of the following does tcp provide (tcp提供了下面的哪一个功能)？
a. unreliable data stream
b. connectionless virtual circuit
c. flow control
d. structured byte stream movement
31) of the following, which field is not a part of the tcp header (在下面各项中，哪一个字
