quiz 3.txt

这是 ssd8 exam1 的选择题 比较全 感兴趣的 朋友 可以 参考一下

  (a) none
 (b) II only
 (c) I and II only
 (d) I, II, and III  

 Correct answer is  (c)  

 Your score on this question is: 0.00  

 Feedback: 
   See section 1.3.2 of the course notes.  
 

 2. 
 A router is installed to interconnect 4 subnetworks with MTUs of 1024, 2048, 576, and 1556 bytes respectively. Nodes A and B are connected to the first and second subnets respectively. An application on node A sends a 4096 byte datagram (e.g. using UDP) to an application on node B. How many incoming IP headers will the router process that have the MF (more fragments) flag set?  
 

  (a) 4
 (b) 5
 (c) 1
 (d) 0  

 Correct answer is  (a)  

 Your score on this question is: 0.00  

 Feedback: 
   See section 1.3.4 of the course notes.  
 

 1. 
 The network interface card of a Web server that you manage has developed sporadic problems. You measure the packet loss rate from your desktop computer and immediately decide to replace the network card. After this simple operation, the Web server successfully rejoins the network, as confirmed by your officemate using her desktop computer. You eagerly go to your desktop to measure the improvement, but find instead that the Web server is not responding to any of your packets. What is your diagnosis?  
 

  (a) The new network card does not work.
 (b) The Domain Name System (DNS) has not yet updated its entry for the Web server.
 (c) Your desktop computer's network card does not work.
 (d) Your desktop computer is still trying to contact the server's old network card.  

 Correct answer is  (d)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.5 of the course notes.  
 

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 2. 
 A corporate information systems manager is interested in collecting statistics on the frequency of computer failures within the organization. Most failures result in an automatic reboot, so the failed computer is typically back on the network in less than a minute. The corporate network connects 1,500 computers in far-flung locations to which the average latency of a packet is 40 milliseconds. The manager asks you to write a tool that will collect the times at which failures occurred in which computers. She wants it by tomorrow, so the tool will have to be simple. On which protocol will you base your implementation?  
 

  (a) PLM
 (b) TCP
 (c) SNMP
 (d) ICMP (ping)  

 Correct answer is  (c)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.6 of the course notes.  
 

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 3. 
 At which of the following layers of the OSI protocol stack can the Internet Control Message Protocol be implemented? 
Network 
Transport 
Data link 
 
 

  (a) I only
 (b) III only
 (c) II only
 (d) I or II only  

 Correct answer is  (a)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.6 of the course notes.  
 

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 4. 
 The Internet Protocol (IP) is used in the network layer of the Internet. Which service does IP provide to the transport layer?  
 

  (a) Connectionless service via datagrams
 (b) Connection-oriented service via datagrams
 (c) Connectionless service via virtual circuits
 (d) Connection-oriented service via virtual circuits  

 Correct answer is  (a)  

 Your score on this question is: 0.00  

 Feedback: 
   See section 1.3.1 of the course notes.  
 

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 5. 
 A router is installed to interconnect 4 subnetworks with MTUs of 1024, 2048, 576, and 1556 bytes respectively. Nodes A and B are connected to the first and second subnets, respectively. An application on node A sends a 4096-byte datagram (e.g., using UDP) to an application on node B. How many IP fragments will the router process as a result?  
 

  (a) 1
 (b) 4
 (c) 2
 (d) 5  

 Correct answer is  (d)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.4 of the course notes.  
 

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 6. 
 A router is installed to interconnect 4 subnetworks with MTUs of 1024, 2048, 576, and 1556 bytes respectively. Nodes A and B are connected to the first and second subnets respectively. An application on node A sends a 4096 byte datagram (e.g. using UDP) to an application on node B. How many incoming IP headers will the router process that have the MF (more fragments) flag set?  
 

  (a) 4
 (b) 1
 (c) 0
 (d) 5  

 Correct answer is  (a)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.4 of the course notes.  
 

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 7. 
 Which of the following benefit from "tunneling" IP datagrams by conveying them inside other packets? 
Mobile IP 
Multicast 
Roll-out of IPv6 
 
 

  (a) I, II and III
 (b) I and III only
 (c) II only
 (d) none  

 Correct answer is  (a)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.8 of the course notes.  
 

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 8. 
 A modification is proposed to the IP protocol that would eliminate the "Identification" and "Fragment Offset" fields from the IP header. This could result in nearly a 15% improvement in the throughput of a link used for short transactions. Which other effects would this proposal have? 
The resulting internetwork would no longer be able to interconnect subnetworks of any kind. 
The scalability of the routing protocol would improve. 
Data delivery would be more robust in the presence of congestion. 
 
 

  (a) I only
 (b) I and II only
 (c) none
 (d) III only  

 Correct answer is  (a)  

 Your score on this question is: 0.00  

 Feedback: 
   See section 1.3.4 of the course notes.  
 

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 9. 
 Using the Domain Name System, we can find 
that 204.194.30.130 is the IP address of www.example.com 
that ns.watson.ibm.com knows how to handle email for all IBM employees 
that a datagram for an IBM address in India will be routed through an Internet IBM router named ibm-gw.customer.ibm.net in New York 
 
 

  (a) I only
 (b) I and II only
 (c) I, II, and III
 (d) II and III only  

 Correct answer is  (b)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.5 of the course notes.  
 

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 10. 
 The Internet Protocol (IP) 
is the only network-layer protocol 
is required of hosts on the Internet 
is the body of standard protocols in use on the Internet 
 
 

  (a) I and II only
 (b) II only
 (c) I only
 (d) II and III only  

 Correct answer is  (b)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.1 of the course notes.  
 

1. 
 A router is installed to interconnect 4 subnetworks with MTUs of 1024, 2048, 576, and 1556 bytes respectively. Nodes A and B are connected to the first and second subnets respectively. An application on node A sends a 4096 byte datagram (e.g. using UDP) to an application on node B. How many incoming IP headers will the router process that have the MF (more fragments) flag set?  
 

  (a) 1
 (b) 4
 (c) 0
 (d) 5  

 Correct answer is  (b)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.4 of the course notes.  
 

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 2. 
 The main network engineer of a large corporation is charged with designing and deploying the company's intranet. She has decided to use a connection-oriented network layer. Which of the following concerns do you think motivated her choice?  
 

  (a) Cost of short transactions—e.g., credit card charge approval.
 (b) Ability to re-route traffic around congested links
 (c) Cost of the routers as the network grows
 (d) Ability to reserve bandwidth—e.g., for important presentations to the Board  

 Correct answer is  (d)  

 Your score on this question is: 0.00  

 Feedback: 
   See section 1.3.1 of the course notes.  
 

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 3. 
 After coming back from a vacation, you are eager to read your mail. You have several email accounts. One of them is served from hotmail.com, so you open up your browser and try to go to www.hotmail.com. Unfortunately, www.hotmail.com is down at the moment. 
Because of this, which of the following packet types have traversed your ISP's router?

ARP 
DNS 
IP 
 
 

  (a) II only
 (b) none
 (c) I, II, and III
 (d) II and III only  

 Correct answer is  (d)  

 Your score on this question is: 0.00  

 Feedback: 
   See section 1.3.5 of the course notes.  
 

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 4. 
 The network interface card of a Web server that you manage has developed sporadic problems. You measure the packet loss rate from your desktop computer and immediately decide to replace the network card. After this simple operation, the Web server successfully rejoins the network, as confirmed by your officemate using her desktop computer. You eagerly go to your desktop to measure the improvement, but find instead that the Web server is not responding to any of your packets. What is your diagnosis?  
 

  (a) The Domain Name System (DNS) has not yet updated its entry for the Web server.
 (b) Your desktop computer is still trying to contact the server's old network card.
 (c) Your desktop computer's network card does not work.
 (d) The new network card does not work.  

 Correct answer is  (b)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.5 of the course notes.  
 

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 5. 
 The class B IP network 128.2.x.x has been assigned to Carnegie Mellon University. To relieve congestion in its internal LAN, Carnegie Mellon has decided to subnet this IP network. This will have which of the following consequences? 
The configuration of the subnets will have to be announced to routers all over the world by notifying NIC and/or IANA. 
A computer may need to change its IP address when moved from one office to another. 
Some bridges, hubs, or switches will need to be replaced with routers. 
 
 

  (a) I, II, and III
 (b) I and III only
 (c) II and III only
 (d) III only  

 Correct answer is  (c)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.3 of the course notes.  
 

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 6. 
 The Internet Protocol (IP) 
is the only network-layer protocol 
is required of hosts on the Internet 
is the body of standard protocols in use on the Internet 
 
 

  (a) II and III only
 (b) II only
 (c) I only
 (d) I and II only  

 Correct answer is  (b)  

 Your score on this question is: 0.00  

 Feedback: 
   See section 1.3.1 of the course notes.  
 

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 7. 
 The IP address space is organized in a hierarchy 
to make the routing task more scalable 
to decrease inefficient fragmentation of the address space 
to give institutions managing local-area networks autonomous control over the assignment of addresses to computers 
 
 

  (a) none
 (b) I only
 (c) I and III only
 (d) II only  

 Correct answer is  (c)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.3 of the course notes.  
 

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 8. 
 In contrast to the Address Resolution Protocol (ARP), the Domain Name System (DNS)  
 

  (a) is not used to find hosts within a LAN
 (b) caches values
 (c) is not used to find host addresses
 (d) can use the same algorithm on all physical network technologies  

 Correct answer is  (d)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.5 of the course notes.  
 

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 9. 
 The following Java declaration 
InetAddress addr = InetAddress.getbyName("www.example.com");

will fail when  
 

  (a) www.example.com does not respond to ARP requests
 (b) www.example.com is down
 (c) all known DNS servers are down
 (d) a route to www.example.com is not available  

 Correct answer is  (c)  

 Your score on this question is: 0.00  

 Feedback: 
   See Chapter 10 of the yellow book. See section 1.3.5 of the course notes.