| 61. | In the TCP/IP protocol suite, which one of the following is NOT part of the IP header? |
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Answer: (d).Destination port number
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| 62. | Suppose that the maximum transmit window size for a TCP connection is 12000 bytes. Each packet consists of 2000 bytes. At some point of time, the connection is in slow-start phase with a current transmit window of 4000 bytes. Subsequently, the transmitter receives two acknowledgements. Assume that no packets are lost and there are no time-outs. What is the maximum possible value of the current transmit window? |
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Answer: (b).8000 bytes
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| 63. | Traceroute reports a possible route that is taken by packets moving from some host A to some other host B. Which of the following options represents the technique used by traceroute to identify these hosts |
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Answer: (a).By progressively querying routers about the next router on the path to B using ICMP packets, starting with the first router
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| 64. | Count to infinity is a problem associated with |
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Answer: (b).distance vector routing protocol
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| 65. | In a communication network, a packet of length L bits takes link L1 with a probability of p1or link L2 with a probability of p2. Link L1 and L2 have bit error probability of b1 and b2 respectively. The probability that the packet will be received without error via either L1 or L2 is |
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Answer: (a).(1 - b1)Lp1 + (1 - b2)Lp2
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| 66. | A company has a class C network address of 204.204.204.0. It wishes to have three subnets, one with 100 hosts and two with 50 hosts each. Which one of the following options represents a feasible set of subnet address/subnet mask pairs? |
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Answer: (d).204.204.204.128/255.255.255.128 204.204.204.64/255.255.255.192 204.204.204.0/255.255.255.192
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| 67. | Assume that "host1.mydomain.dom" has an IP address of 145.128.16.8. Which of the following options would be most appropriate as a subsequence of steps in performing the reverse lookup of 145.128.16.8? In the following options "NS" is an abbreviation of "nameserver". |
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Answer: (c).Query a NS for in-addr.arpa and then a NS for 128.145.in-addr.arpa domains
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| 68. | An IP datagram of size 1000 bytes arrives at a router. The router has to forward this packet on a link whose MTU (maximum transmission unit) is 100 bytes. Assume that the size of the IP header is 20 bytes. The number of fragments that the IP datagram will be divided into for transmission is : |
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Answer: (d).13
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| 69. | Which of the following statements is TRUE ? |
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Answer: (c).Ethernet frame includes a CRC field and IP packet includes a checksum field
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| 70. | Two popular routing algorithms are Distance Vector(DV) and Link State (LS) routing. Which of the following are true? (S1) Count to infinity is a problem only with DV and not LS routing (S2) In LS, the shortest path algorithm is run only at one node (S3) In DV, the shortest path algorithm is run only at one node (S4) DV requires lesser number of network messages than LS |
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Answer: (d).S1 and S4 only
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