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

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 10. 
 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) 5
 (c) 2
 (d) 4  

 Correct answer is  (b)  


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 IP fragments will the router process as a result?  
 

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

 Correct answer is  (c)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.4 of the course notes.  
 

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 2. 
 In contrast to the Address Resolution Protocol (ARP), the Domain Name System (DNS)  
 

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

 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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 3. 
 In a network that uses shortest-path-per-hop routing, router A receives a datagram destined for host H and determines that the shortest path to H traverses routers B, C, and D, in that order. The datagram may traverse 
B and D, but not C 
B, C, and D, in that order 
C and D, but not B 
 
 

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

 Correct answer is  (c)  

 Your score on this question is: 0.00  

 Feedback: 
   See section 1.3.2 of the course notes.
   (b) B may have a different shortest path to D, unbeknownst to A  
 

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 4. 
 At which of the following layers of the OSI protocol stack can the Internet Control Message Protocol be implemented? 
Network 
Transport 
Data link 
 
 

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

 Correct answer is  (b)  

 Your score on this question is: 0.00  

 Feedback: 
   See section 1.3.6 of the course notes.
   (a) A data link layer protocol would not be able to traverse routers.  
 

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 5. 
 The Dynamic Host Configuration Protocol (DHCP) may be used to 
configure the scheduling policy of a busy server 
relieve the saturation of the IP address space 
assign a fixed address to a Web server after a reboot 
 
 

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

 Correct answer is  (c)  

 Your score on this question is: 0.00  

 Feedback: 
   See section 1.3.6 of the course notes.  
 

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 6. 
 Which of the following developments will be facilitated by the widespread deployment of IPv6? 
Every appliance can become an Internet node 
Doubling in reliability of data links between routers 
Elimination of IP address "spoofing" (a line of computer attack in which IP datagrams are made to appear to come from a bogus address) 
 
 

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

 Correct answer is  (d)  

 Your score on this question is: 0.00  

 Feedback: 
   See section 1.3.8 of the course notes.  
 

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 7. 
 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, II, and III
 (b) II and III only
 (c) I only
 (d) I and II 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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 8. 
 A difference between routers and switches is that  
 

  (a) routers parse, process, and modify IP headers
 (b) routers perform the same function as switches but the two are marketed in very different ways
 (c) switches hold IP routing tables only for only local subnets
 (d) switches connect only to hosts, whereas routers connect networks  

 Correct answer is  (a)  

 Your score on this question is: 0.00  

 Feedback: 
   See section 1.3.2 of the course notes.
   (d) A switch may connect to a router, a network, another switch, a hub, etc. This is not a difference.  
 

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 9. 
 Which of the following is the most credible threat to the continuing success of the Internet Protocol (IP) as currently deployed?  
 

  (a) Big multimedia files will no longer fit into IP datagrams.
 (b) Widespread deployment of fiber optics will call for more than 8192 fragments per datagram.
 (c) Router memory will become insufficient to keep track of an exponentially increasing number of circuits.
 (d) The IP address space will be exhausted.  

 Correct answer is  (d)  

 Your score on this question is: 0.00  

 Feedback: 
   See section 1.3.3 of the course notes.  
 

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 10. 
 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) none
 (b) I and II only
 (c) III only
 (d) I only  

 Correct answer is  (d)  



 1. 
 A network uses a routing algorithm that uses paths with the least number of hops. These paths are computed periodically using a shortest-path algorithm. In this network, datagrams 
are routed around congested links 
may traverse the same router twice 
will always reach their destination 
 
 

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

 Correct answer is  (d)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.2 of the course notes.  
 

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 2. 
 In contrast to the Address Resolution Protocol (ARP), the Domain Name System (DNS)  
 

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

 Correct answer is  (c)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.5 of the course notes.  
 

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 3. 
 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 and II only
 (b) III only
 (c) none
 (d) I only  

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

 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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 5. 
 Which of the following is the most credible threat to the continuing success of the Internet Protocol (IP) as currently deployed?  
 

  (a) The IP address space will be exhausted.
 (b) Big multimedia files will no longer fit into IP datagrams.
 (c) Router memory will become insufficient to keep track of an exponentially increasing number of circuits.
 (d) Widespread deployment of fiber optics will call for more than 8192 fragments per datagram.  

 Correct answer is  (a)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.3 of the course notes.  
 

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 6. 
 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 and II only
 (b) II and III only
 (c) I, II, and III
 (d) I only  

 Correct answer is  (a)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.5 of the course notes.  
 

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 7. 
 In a network that uses shortest-path-per-hop routing, router A receives a datagram destined for host H and determines that the shortest path to H traverses routers B, C, and D, in that order. The datagram may traverse 
B and D, but not C 
B, C, and D, in that order 
C and D, but not B 
 
 

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

 Correct answer is  (a)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.2 of the course notes.  
 

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 8. 
 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) Your desktop computer is still trying to contact the server's old network card.
 (b) Your desktop computer's network card does not work.
 (c) The new network card does not work.
 (d) The Domain Name System (DNS) has not yet updated its entry for the Web server.  

 Correct answer is  (a)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.5 of the course notes.  
 

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 9. 
 A difference between routers and switches is that  
 

  (a) routers parse, process, and modify IP headers
 (b) switches connect only to hosts, whereas routers connect networks
 (c) switches hold IP routing tables only for only local subnets
 (d) routers perform the same function as switches but the two are marketed in very different ways  

 Correct answer is  (a)  

 Your score on this question is: 10.00  

 Feedback: 
   See section 1.3.2 of the course notes.  
 

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 10. 
 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) II only
 (c) I only
 (d) I and III only  

 Correct answer is  (d)