Gate MCQ Quiz Hub

GATE STUDY MATERIAL /NETWORKING SET 3

Choose a topic to test your knowledge and improve your Gate skills

1. In the following pairs of OSI protocol layer/sub-layer and its functionality, the INCORRECT pair is




2. Choose the best matching between Group 1 and Group 2. Group-1 Group-2 P. Data link 1. Ensures reliable transport of data over a physical point-to-point link Q. Network layer 2. Encoder/decodes data for physical transmission R. Transport layer 3. Allows end-to-end communication between two processes 4. Routes data from one network node to the next




3. Which of the following is NOT true with respect to a transparent bridge and a router?




4. Host A sends a UDP datagram containing 8880 bytes of user data to host B over an Ethernet LAN. Ethernet frames may carry data up to 1500 bytes (i.e. MTU = 1500 bytes). Size of UDP header is 8 bytes and size of IP header is 20 bytes. There is no option field in IP header. How may total number of IP fragments will be transmitted and what will be the contents of offset field in the last fragment?




5. Since it is a network that uses switch, every packet goes through two links, one from source to switch and other from switch to destination. Since there are 10000 bits and packet size is 5000, two packets are sent. Transmission time for each packet is 5000 / 10^7 bits per second links. Each link has a propagation delay of 20 microseconds. The switch begins forwarding a packet 35 microseconds after it receives the same. If 10000 bits of data are to be transmitted between the two hosts using a packet size of 5000 bits, the time elapsed between the transmission of the first bit of data and the reception of the last bit of the data in microseconds is _________.




6. Which one of the following statements is FALSE?




7. Which one of the following statements is FALSE?




8. A serial transmission Ti uses 8 information bits, 2 start bits, 1 stop bit and 1 parity bit for each character. A synchronous transmission T2 uses 3 eight bit sync characters followed by 30 eight bit information characters. If the bit rate is 1200 bits/second in both cases, what are the transfer rates of Ti and T2?




9. In a sliding window ARQ scheme, the transmitter's window size is N and the receiver's window size is M. The minimum number of distinct sequence numbers required to ensure correct operation of the ARQ scheme is




10. Which one of the following protocols is NOT used to resolve one form of address to another one?




11. Identify the correct sequence in which the following packets are transmitted on the network by a host when a browser requests a webpage from a remote server, assuming that the host has just been restarted.




12. A firewall is to be configured to allow hosts in a private network to freely open TCP connections and send packets on open connections. However, it will only allow external hosts to send packets on existing open TCP connections or connections that are being opened (by internal hosts) but not allow them to open TCP connections to hosts in the private network. To achieve this the minimum capability of the firewall should be that of




13. Which protocol will be used to automate the IP configuration mechanism which includes IP address, subnet mask, default gateway, and DNS information?




14. In Go–back 3 flow control protocol every 6th packet is lost. If we have to send 11 packets. How many transmissions will be needed ?




15. What will be the total minimum bandwidth of the channel required for 7 channels of 400 kHz bandwidth multiplexed together with each guard band of 20 kHz?




16. Which of the following is false:




17. The subnet mask for a particular network is 255.255.31.0. Which of the following pairs of IP addresses could belong to this network?




18. Which of the following protocol is called as byte-oriented protocol?




19. If syn = 0 and ack = 1, it indicates




20. A DNS.....................server gets its data from another DNS server.




21. The .............................field in the MIME header describes the method used to encode the data.




22. A client message usually needs ........................ to send mail.




23. Which one is not a method of HTTP?




24. Which one of the following is a communication protocol used for email?




25. Which one of the following statement about email is false?




26. Which one of the following can be used on the IP network to monitor a router?




27. Which of the following is true?




28. Which of the following is not a Block cipher?




29. In a ................................attack, an intruder comes between two communicating parties, Intercepting and replying to their messages.




30. A computer crime is




31. In RSA.............................in the common factor in both keys?




32. Programs that come into a computer system disguised as something else are called




33. Having a(n) .....................................is important to help large Organization continue operating until Normal computer operations.




34. In what way does a firewall increase the securities of a VPN?




35. Choose the false one.




36. There are 15 users communicating to each other. How many pairs of keys are required to authenticate the communications if the symmetric key is used?




37. Let the value of the RTT(Round-Trip-Time)is to be measure (d). The value of the previous RTT be 350μs. Let the value of α be 90% the new RTT, hence the retransmission time is ______ .(Assume it takes a segment at this moment to be acknowledged in 90μs)




38. Suppose a web server application generates messages consisting of 120 bytes if every second to the Central host, and each message gets encapsulated in a UDP segment and then an IPV4 Datagram. There are no options added in the TCP (or) Ip headers. What percentage of each Datagram will consist of data generated by the application?




39. Suppose that a TCP entity receives 2 MB file from the application layer and the IP layer is willing to Carry blocks of maximum size 1600 B; calculate the amount of overhead incurred from Segmenting the file into packet-sized units. Assume both TCP and Ip header of 20 B.