UGC NET Paper 2 Computer Science – Unit 9: Data Communication and Computer Networks PYQ (December 2022 Shift 1)

Q33. Which protocol is used to acquire the MAC address of a host whose IP address is known?

Q34. In CRC coding, the data word is 111111, the divisor is 1010 and the remainder is 110. Which of the following is the codeword?

Q35. In the Go-Back-N protocol, Sf (first outstanding packet) = 3 and Sn (next packet to send) = 7. After receiving the packet with AckNo = 6, the value of Sn is ______

Q36. What is the minimum Hamming distance in a block code if we want to be able to detect up to S errors?

Q61. A network uses distance-vector routing. Router R has neighbours X, Y and Z at distances 3, 2 and 5. Their vectors report distances to router P of 7, 6 and 5, and to router Q of 4, 6 and 8, respectively. Which statements are true for R's new routing table after this iteration?
A. The distance from R to P will be stored as 10.
B. The distance from R to Q will be stored as 7.
C. The next hop from R to P is Y.
D. The next hop from R to Q is Z.
Choose the correct answer from the options given below:

Q62. A router's table has subnets 12.20.164.0/22 → R1, 12.20.170.0/23 → R2, 12.20.168.0/23 → Interface 0, 12.20.166.0/23 → Interface 1 and a default → R3. Which of the following prefixes can collectively be used to correctly aggregate all of the subnets?
A. 12.20.164.0/20
B. 12.20.164.0/22
C. 12.20.164.0/21
D. 12.20.168.0/22
Choose the correct answer from the options given below:

Q63. Hosts P and Q are connected through router R. The MTU of link P–R is 1500 bytes and of R–Q is 820 bytes. A TCP segment of 1400 bytes is sent from P to Q with IP identification 0x1234; the IP header is 20 bytes and DF is not set. Which statements are NOT true?
A. Two fragments are created at R, and the IP datagram carrying the second fragment is 620 bytes.
B. If the second fragment is lost, R resends the fragment with IP identification 0x1234.
C. If the second fragment is lost, P is required to resend the entire TCP segment.
D. The TCP destination port can be determined by analysing the second fragment only.
Choose the correct answer from the options given below:

Q74. Match List I with List II

List I	List II
A. Physical Layer	I. Transforming the raw bits into frames for transmission
B. Data Link Layer	II. Control and monitoring of subnet
C. Network Layer	III. Transmission of raw bits over a communication channel
D. Transport Layer	IV. Transmits data connection-oriented or connectionless (datagrams)

Q84. Arrange the following steps of RSA key generation in the correct order:
A. Choose an integer e such that 1 < e < λ(n)
B. Compute n = p × q
C. Find d ≡ e⁻¹ (mod λ(n))
D. Choose two large prime numbers p and q
E. Compute λ(n)
Choose the correct answer from the options given below: