Previous year questions
Computer Networks
142 questions from GATE CS 2011 to 2026, newest first.
Topics
- OSI/TCP-IP Layering, Physical Layer and Switching 16
- Data Link Layer: Framing, Error Detection and Sliding Window 23
- Medium Access Control (ALOHA, CSMA/CD) and Ethernet/Switching 10
- IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT 34
- Routing Algorithms (Distance Vector, Link State) and BGP/OSPF 15
- Transport Layer: UDP, TCP Flow and Congestion Control, Sockets 27
- Application Layer: DNS, HTTP, SMTP, FTP 29
All Computer Networks questions
GATE CS 2026 Set 1, Q.18
With respect to a TCP connection between a client and a server, which one of the following statements is true?
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2026 Set 1, Q.19
Which of the following statements is/are true with respect to the interaction of a web browser with a web server using HTTP 1.1?
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2026 Set 1, Q.44
A TCP sender successfully establishes a connection with a TCP receiver and starts the transmission of segments. The TCP congestion control mechanism's slow-start threshold is se...
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2026 Set 1, Q.45
Consider the implementation of sliding window protocol over a lossless link, with a window size of frames, where each frame is of size bits (including header). The ba...
Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2026 Set 1, Q.56
An ISP having an address block
202.16.0.0/15assigns a block of IP addresses to a client, using the classless internet domain routing (CIDR) super-netting approach. Whi...IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2026 Set 2, Q.21
Consider a file of size 4 million bytes being transferred between two hosts connected via a path consisting of three consecutive links of bandwidth 2 Mbps, 500 kbps, and 1 Mbps,...
OSI/TCP-IP Layering, Physical Layer and Switching
GATE CS 2026 Set 2, Q.22
Which one of the following protocols may need to broadcast some of its messages?
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2026 Set 2, Q.33
If an IP network uses a subnet mask of
255.255.240.0, the maximum number of IP addresses that can be assigned to network interfaces is __________. (answer in integer)IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2026 Set 2, Q.43
Consider the transmission of data bits
110001011over a link that uses Cyclic Redundancy Check (CRC) code for error detection. If the generator bit pattern is given to be…Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2026 Set 2, Q.58
Consider a new TCP connection between a sender and a receiver. The receiver advertised window is constant at 48 KB, the maximum segment size (MSS) is 2 KB, and the slow start th...
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2026 Set 2, Q.65
It is necessary to design a link-layer protocol between two hosts that are directly connected over a lossless link of length 3000 kilometers. Assume that the link bandwidth is…
Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2025 Set 1, Q.16
Identify the ONE CORRECT matching between the OSI layers and their corresponding functionalities as shown. OSI Layers Functionalities (a) Network layer (I) Packet routing (b) Tr...
OSI/TCP-IP Layering, Physical Layer and Switching
GATE CS 2025 Set 1, Q.22
Consider the 3-way handshaking protocol for TCP connection establishment. Let the three packets exchanged during the connection establishment be denoted as P1, P2, and P3, in or...
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2025 Set 1, Q.40
A packet with the destination IP address
145.36.109.70arrives at a router whose routing table is shown. Which interface will the packet be forwarded to? Subnet Address Subnet...IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2025 Set 1, Q.56
Suppose a 5-bit message is transmitted from a source to a destination through a noisy channel. The probability that a bit of the message gets flipped during transmission is…
Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2025 Set 1, Q.57
Suppose a message of size 15000 bytes is transmitted from a source to a destination using IPv4 protocol via two routers as shown in the figure. Each router has a defined maximum...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2025 Set 2, Q.16
Consider the following statements: (i) Address Resolution Protocol (ARP) provides a mapping from an IP address to the corresponding hardware (link-layer) address. (ii) A single...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT · Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2025 Set 2, Q.17
Consider the routing protocols given in List I and the names given in List II: List I List II (i) Distance vector routing (a) Bellman-Ford (ii) Link state routing (b) Dijkstra F...
Routing Algorithms (Distance Vector, Link State) and BGP/OSPF
GATE CS 2025 Set 2, Q.18
A machine receives an IPv4 datagram. The protocol field of the IPv4 header has the protocol number of a protocol X. Which ONE of the following is NOT a possible candidate for X?
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT · Routing Algorithms (Distance Vector, Link State) and BGP/OSPF
GATE CS 2025 Set 2, Q.23
Consider a network that uses Ethernet and IPv4. Assume that IPv4 headers do not use any options field. Each Ethernet frame can carry a maximum of 1500 bytes in its data field. A...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2025 Set 2, Q.36
Suppose we are transmitting frames between two nodes using Stop-and-Wait protocol. The frame size is 3000 bits. The transmission rate of the channel is 2000 bps (bits/second) an...
Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2024 Set 1, Q.16
A user starts browsing a webpage hosted at a remote server. The browser opens a single TCP connection to fetch the entire webpage from the server. The webpage consists of a top-...
Application Layer: DNS, HTTP, SMTP, FTP · Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2024 Set 1, Q.29
TCP client P successfully establishes a connection to TCP server Q. Let denote the sequence number in the SYN sent from P to Q. Let denote the acknowledgement number...
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2024 Set 1, Q.31
Which of the following fields is/are modified in the IP header of a packet going out of a network address translation (NAT) device from an internal network to an external network?
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2024 Set 1, Q.36
Consider a network path P-Q-R between nodes P and R via router Q. Node P sends a file of size bytes to R via this path by splitting the file into chunks of bytes e...
OSI/TCP-IP Layering, Physical Layer and Switching
GATE CS 2024 Set 1, Q.58
Consider the entries shown below in the forwarding table of an IP router. Each entry consists of an IP prefix and the corresponding next hop router for packets whose destination...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2024 Set 1, Q.65
Consider sending an IP datagram of size 1420 bytes (including 20 bytes of IP header) from a sender to a receiver over a path of two links with a router between them. The first l...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2024 Set 2, Q.23
Node X has a TCP connection open to node Y. The packets from X to Y go through an intermediate IP router R. Ethernet switch S is the first switch on the network path between X a...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT · OSI/TCP-IP Layering, Physical Layer and Switching
GATE CS 2024 Set 2, Q.28
Which of the following statements about IPv4 fragmentation is/are TRUE?
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2024 Set 2, Q.32
Which of the following fields of an IP header is/are always modified by any router before it forwards the IP packet?
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2024 Set 2, Q.38
Which one of the following CIDR prefixes exactly represents the range of IP addresses
10.12.2.0to10.12.3.255?IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2024 Set 2, Q.54
Consider a TCP connection operating at a point of time with the congestion window of size 12 MSS (Maximum Segment Size), when a timeout occurs due to packet loss. Assuming that...
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2024 Set 2, Q.55
Consider an Ethernet segment with a transmission speed of bits/sec and a maximum segment length of 500 meters. If the speed of propagation of the signal in the medium is...
Medium Access Control (ALOHA, CSMA/CD) and Ethernet/Switching
GATE CS 2023, Q.17
Suppose two hosts are connected by a point-to-point link and they are configured to use Stop-and-Wait protocol for reliable data transfer. Identify in which of the following sce...
Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2023, Q.25
Which of the following statements is/are INCORRECT about the OSPF (Open Shortest Path First) routing protocol used in the Internet?
Routing Algorithms (Distance Vector, Link State) and BGP/OSPF
GATE CS 2023, Q.50
Suppose you are asked to design a new reliable byte-stream transport protocol like TCP. This protocol, named myTCP, runs over a 100 Mbps network with Round Trip Time of 150 mill...
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2023, Q.52
Suppose in a web browser, you click on the www.gate-2023.in URL. The browser cache is empty. The IP address for this URL is not cached in your local host, so a DNS lookup is tri...
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2023, Q.65
The forwarding table of a router is shown below. Subnet Number Subnet Mask Interface ID 200.150.0.0 255.255.0.0 1 200.150.64.0 255.255.224.0 2 200.150.68.0 255.255.255.0 3 200.1...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT · Routing Algorithms (Distance Vector, Link State) and BGP/OSPF
GATE CS 2022, Q.22
Consider an enterprise network with two Ethernet segments, a web server and a firewall, connected via three routers as shown below. Enterprise network with Firewall connected to...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2022, Q.35
Consider the resolution of the domain name www.gate.org.in by a DNS resolver. Assume that no resource records are cached anywhere across the DNS servers and that iterative query...
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2022, Q.55
Consider routing table of an organization’s router shown below: | Subnet Number | Subnet Mask | Next Hop | | :--- | :--- | :--- | | 12.20.164.0 | 255.255.252.0 | R1 | | 12.20.17...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2022, Q.57
Consider a network with three routers P, Q, R shown in the figure below. All the links have cost of unity. Three routers P, Q, and R connected in a line: P connected to Q, and Q...
Routing Algorithms (Distance Vector, Link State) and BGP/OSPF
GATE CS 2022, Q.59
Consider a 100 Mbps link between an earth station (sender) and a satellite (receiver) at an altitude of 2100 km. The signal propagates at a speed of ....
OSI/TCP-IP Layering, Physical Layer and Switching
GATE CS 2022, Q.60
Consider the data transfer using TCP over a 1 Gbps link. Assuming that the maximum segment lifetime (MSL) is set to 60 seconds, the minimum number of bits required for the seque...
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2021 Set 1, Q.18 (CS Q.8)
Consider the following two statements. : Destination MAC address of an ARP reply is a broadcast address. : Destination MAC address of an ARP request is a broadcast add...
Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2021 Set 1, Q.39 (CS Q.29)
Assume that a 12-bit Hamming codeword consisting of 8-bit data and 4 check bits is , where the data bits and the check bits are...
Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2021 Set 1, Q.54 (CS Q.44)
A TCP server application is programmed to listen on port number on host . A TCP client is connected to the TCP server over the network. Consider that while the TCP connec...
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2021 Set 1, Q.55 (CS Q.45)
Consider two hosts and connected through a router . The maximum transfer unit (MTU) value of the link between and is 1500 bytes, and between and is 82...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2021 Set 1, Q.59 (CS Q.49)
Consider the sliding window flow-control protocol operating between a sender and a receiver over a full-duplex error-free link. Assume the following: - The time taken for proces...
Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2021 Set 2, Q.17 (CS Q.7)
Consider the three-way handshake mechanism followed during TCP connection establishment between hosts and . Let and be two random 32-bit starting sequence numbers...
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2021 Set 2, Q.44 (CS Q.34)
Consider the cyclic redundancy check (CRC) based error detecting scheme having the generator polynomial . Suppose the message is to be...
Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2021 Set 2, Q.55 (CS Q.45)
Consider a computer network using the distance vector routing algorithm in its network layer. The partial topology of the network is as shown below. A distance vector routing ne...
Routing Algorithms (Distance Vector, Link State) and BGP/OSPF
GATE CS 2021 Set 2, Q.64 (CS Q.54)
Consider a network using the pure ALOHA medium access control protocol, where each frame is of length 1,000 bits. The channel transmission rate is 1 Mbps ( bits per seco...
Medium Access Control (ALOHA, CSMA/CD) and Ethernet/Switching
GATE CS 2020, Q.25 (CS Q.15)
Consider the following statements about the functionality of an IP based router. I. A router does not modify the IP packets during forwarding. II. It is not necessary for a rout...
Routing Algorithms (Distance Vector, Link State) and BGP/OSPF · IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2020, Q.35 (CS Q.25)
Assume that you have made a request for a web page through your web browser to a web server. Initially the browser cache is empty. Further, the browser is configured to send HTT...
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2020, Q.48 (CS Q.38)
An organization requires a range of IP addresses to assign one to each of its 1500 computers. The organization has approached an Internet Service Provider (ISP) for this task. T...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2020, Q.65 (CS Q.55)
Consider a TCP connection between a client and a server with the following specifications: the round trip time is 6 ms, the size of the receiver advertised window is 50 KB, slow...
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2019, Q.26 (CS Q.16)
Which of the following protocol pairs can be used to send and retrieve e-mails (in that order)?
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2019, Q.38 (CS Q.28)
Consider three machines M, N, and P with IP addresses 100.10.5.2, 100.10.5.5, and 100.10.5.6 respectively. The subnet mask is set to 255.255.255.252 for all the three machines....
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2019, Q.39 (CS Q.29)
Suppose that in an IP-over-Ethernet network, a machine X wishes to find the MAC address of another machine Y in its subnet. Which one of the following techniques can be used for...
Routing Algorithms (Distance Vector, Link State) and BGP/OSPF
GATE CS 2019, Q.59 (CS Q.49)
Consider that 15 machines need to be connected in a LAN using 8-port Ethernet switches. Assume that these switches do not have any separate uplink ports. The minimum number of s...
Medium Access Control (ALOHA, CSMA/CD) and Ethernet/Switching · OSI/TCP-IP Layering, Physical Layer and Switching
GATE CS 2019, Q.64 (CS Q.54)
In an RSA cryptosystem, the value of the public modulus parameter is 3007. If it is also known that , where denotes Euler's Totient Function, then t...
Application Layer: DNS, HTTP, SMTP, FTP · Sets, Relations, Functions, Partial Orders and Lattices
GATE CS 2018, Q.23 (CS Q.13)
Match the following: Field Length in bits P. UDP Header’s Port Number I. 48 Q. Ethernet MAC Address II. 8 R. IPv6 Next Header III. 32 S. TCP Header’s Sequence Number IV. 16
OSI/TCP-IP Layering, Physical Layer and Switching
GATE CS 2018, Q.24 (CS Q.14)
Consider the following statements regarding the slow start phase of the TCP congestion control algorithm. Note that cwnd stands for the TCP congestion window and MSS denotes the...
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2018, Q.35 (CS Q.25)
Consider a long-lived TCP session with an end-to-end bandwidth of 1 Gbps (= bits-per-second). The session starts with a sequence number of 1234. The minimum time (in seco...
OSI/TCP-IP Layering, Physical Layer and Switching
GATE CS 2018, Q.64 (CS Q.54)
Consider an IP packet with a length of 4,500 bytes that includes a 20-byte IPv4 header and a 40-byte TCP header. The packet is forwarded to an IPv4 router that supports a Maximu...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2018, Q.65 (CS Q.55)
Consider a simple communication system where multiple nodes are connected by a shared broadcast medium (like Ethernet or wireless). The nodes in the system use the following car...
OSI/TCP-IP Layering, Physical Layer and Switching
GATE CS 2017 Set 1, Q.14 (CS Q.14)
Consider a TCP client and a TCP server running on two different machines. After completing data transfer, the TCP client calls
closeto terminate the connection and a FIN segm...Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2017 Set 1, Q.15 (CS Q.15)
A sender S sends a message to receiver R, which is digitally signed by S with its private key. In this scenario, one or more of the following security violations can take pl...
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2017 Set 1, Q.32 (CS Q.32)
A computer network uses polynomials over for error checking with 8 bits as information bits and uses as the generator polynomial to generate the che...
Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2017 Set 1, Q.44 (CS Q.44)
In a RSA cryptosystem, a participant A uses two prime numbers and to generate her public and private keys. If the public key of A is 35, then the private key o...
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2017 Set 1, Q.45 (CS Q.45)
The values of parameters for the Stop-and-Wait ARQ protocol are as given below: - Bit rate of the transmission channel = . - Propagation delay from sender to rece...
Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2017 Set 2, Q.9 (CS Q.9)
Consider the following statements about the routing protocols, Routing Information Protocol (RIP) and Open Shortest Path First (OSPF) in an IPv4 network. I: RIP uses distance ve...
Routing Algorithms (Distance Vector, Link State) and BGP/OSPF · Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2017 Set 2, Q.18 (CS Q.18)
Consider socket API on a Linux machine that supports connected UDP sockets. A connected UDP socket is a UDP socket on which
connectfunction has already been called. Which of...Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2017 Set 2, Q.20 (CS Q.20)
The maximum number of IPv4 router addresses that can be listed in the record route (RR) option field of an IPv4 header is
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2017 Set 2, Q.34 (CS Q.34)
Consider a binary code that consists of only four valid codewords as given below:
00000,01011,10101,11110Let the minimum Hamming distance of the code be and the...Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2017 Set 2, Q.35 (CS Q.35)
Consider two hosts and , connected by a single direct link of rate bits/sec. The distance between the two hosts is km and the propagation speed along the...
OSI/TCP-IP Layering, Physical Layer and Switching
GATE CS 2016 Set 1, Q.34 (CS Q.24)
Which one of the following protocols is NOT used to resolve one form of address to another one?
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2016 Set 1, Q.35 (CS Q.25)
Which of the following is/are example(s) of stateful application layer protocols? (i) HTTP (ii) FTP (iii) TCP (iv) POP3
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2016 Set 1, Q.62 (CS Q.52)
Consider that wants to send a message that is digitally signed to . Let the pair of private and public keys for and be denoted by and for…
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2016 Set 1, Q.63 (CS Q.53)
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 o...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2016 Set 1, Q.64 (CS Q.54)
For a host machine that uses the token bucket algorithm for congestion control, the token bucket has a capacity of 1 megabyte and the maximum output rate is 20 megabytes per sec...
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2016 Set 1, Q.65 (CS Q.55)
A sender uses the Stop-and-Wait ARQ protocol for reliable transmission of frames. Frames are of size 1000 bytes and the transmission rate at the sender is 80 Kbps (1Kbps = 1000...
Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2016 Set 2, Q.33 (CS Q.23)
Anarkali digitally signs a message and sends it to Salim. Verification of the signature by Salim requires
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2016 Set 2, Q.34 (CS Q.24)
In an Ethernet local area network, which one of the following statements is TRUE?
Medium Access Control (ALOHA, CSMA/CD) and Ethernet/Switching
GATE CS 2016 Set 2, Q.35 (CS Q.25)
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 h...
Application Layer: DNS, HTTP, SMTP, FTP · Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2016 Set 2, Q.63 (CS Q.53)
A network has a data transmission bandwidth of bits per second. It uses CSMA/CD in the MAC layer. The maximum signal propagation time from one node to another n...
Medium Access Control (ALOHA, CSMA/CD) and Ethernet/Switching · Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2016 Set 2, Q.64 (CS Q.54)
For the IEEE 802.11 MAC protocol for wireless communication, which of the following statements is/are TRUE? I. At least three non-overlapping channels are available for transmis...
Medium Access Control (ALOHA, CSMA/CD) and Ethernet/Switching · Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2016 Set 2, Q.65 (CS Q.55)
Consider a bits/second satellite communication link with one way propagation delay of 150 milliseconds. Selective retransmission (repeat) protocol is used on t...
Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2015 Set 1, Q.25 (CS Q.15)
Which of the following statements is/are FALSE? I. XML overcomes the limitations in HTML to support a structured way of organizing content. II. XML specification is not case sen...
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2015 Set 1, Q.27 (CS Q.17)
In one of the pairs of protocols given below, both the protocols can use multiple TCP connections between the same client and the server. Which one is that?
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2015 Set 1, Q.29 (CS Q.19)
Suppose two hosts use a TCP connection to transfer a large file. Which of the following statements is/are FALSE with respect to the TCP connection? I. If the sequence number of...
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2015 Set 1, Q.31 (CS Q.21)
Suppose that everyone in a group of people wants to communicate secretly with the others using symmetric key cryptographic system. The communication between any two pe...
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2015 Set 1, Q.32 (CS Q.22)
Which one of the following fields of an IP header is NOT modified by a typical IP router?
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2015 Set 1, Q.39 (CS Q.29)
Consider a LAN with four nodes and . Time is divided into fixed-size slots, and a node can begin its transmission only at the beginning of a slot. A collisi...
Medium Access Control (ALOHA, CSMA/CD) and Ethernet/Switching
GATE CS 2015 Set 1, Q.63 (CS Q.53)
Suppose that the stop-and-wait protocol is used on a link with a bit rate of kilobits per second and milliseconds propagation delay. Assume that the transmission time...
Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2015 Set 2, Q.18 (CS Q.8)
A link has a transmission speed of bits/sec. It uses data packets of size 1000 bytes each. Assume that the acknowledgment has negligible transmission delay, and that its...
Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2015 Set 2, Q.23 (CS Q.13)
Which one of the following statements is NOT correct about HTTP cookies?
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2015 Set 2, Q.30 (CS Q.20)
Identify the correct order in which a server process must invoke the function calls
accept,bind,listen, andrecvaccording to UNIX socket APIApplication Layer: DNS, HTTP, SMTP, FTP
GATE CS 2015 Set 2, Q.44 (CS Q.34)
Assume that the bandwidth for a TCP connection is 1048560 bits/sec. Let be the value of RTT in milliseconds (rounded off to the nearest integer) after which the TCP win...
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2015 Set 2, Q.51 (CS Q.41)
Consider the following routing table at an IP router: Network No. Net Mask Next Hop 128.96.170.0 255.255.254.0 Interface 0 128.96.168.0 255.255.254.0 Interface 1 128.96.166.0 25...
Routing Algorithms (Distance Vector, Link State) and BGP/OSPF
GATE CS 2015 Set 2, Q.62 (CS Q.52)
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 U...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2015 Set 3, Q.16 (CS Q.6)
Consider a CSMA/CD network that transmits data at a rate of 100 Mbps ( bits per second) over a 1 km (Kilometer) cable with no repeaters. If the minimum frame size required...
Medium Access Control (ALOHA, CSMA/CD) and Ethernet/Switching
GATE CS 2015 Set 3, Q.18 (CS Q.8)
In a web server, ten WebPages are stored with the URLs of the form
http://www.yourname.com/var.html; where,varis a different number from 1 to 10 for each Webpage. Suppose,...Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2015 Set 3, Q.32 (CS Q.22)
Consider the following statements. I. TCP connections are full duplex II. TCP has no option for selective acknowledgement III. TCP connections are message streams Which of the f...
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2015 Set 3, Q.38 (CS Q.28)
Consider a network connecting two systems located 8000 kilometers apart. The bandwidth of the network is bits per second. The propagation speed of the media is...
Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2015 Set 3, Q.46 (CS Q.36)
Two hosts are connected via a packet switch with bits per second links. Each link has a propagation delay of 20 microseconds. The switch begins forwarding a packet 35 mic...
OSI/TCP-IP Layering, Physical Layer and Switching
GATE CS 2015 Set 3, Q.48 (CS Q.38)
In the network 200.10.11.144/27, the fourth octet (in decimal) of the last IP address of the network which can be assigned to a host is _____.
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2014 Set 1, Q.33 (CS Q.23)
Consider the following three statements about link state and distance vector routing protocols, for a large network with 500 network nodes and 4000 links. [S1] The computational...
Routing Algorithms (Distance Vector, Link State) and BGP/OSPF
GATE CS 2014 Set 1, Q.34 (CS Q.24)
Which of the following are used to generate a message digest by the network security protocols? (P) RSA (Q) SHA-1 (R) DES (S) MD5
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2014 Set 1, Q.35 (CS Q.25)
Identify the correct order in which the following actions take place in an interaction between a web browser and a web server. 1. The web browser requests a webpage using HTTP....
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2014 Set 1, Q.36 (CS Q.26)
Consider a token ring network with a length of 2 km having 10 stations including a monitoring station. The propagation speed of the signal is m/s and the token t...
Medium Access Control (ALOHA, CSMA/CD) and Ethernet/Switching
GATE CS 2014 Set 1, Q.37 (CS Q.27)
Let the size of congestion window of a TCP connection be 32 KB when a timeout occurs. The round trip time of the connection is 100 msec and the maximum segment size used is 2 KB...
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2014 Set 1, Q.38 (CS Q.28)
Consider a selective repeat sliding window protocol that uses a frame size of 1 KB to send data on a 1.5 Mbps link with a one-way latency of 50 msec. To achieve a link utilizati...
Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2014 Set 2, Q.33 (CS Q.23)
Which one of the following is TRUE about the interior gateway routing protocols - Routing Information Protocol (RIP) and Open Shortest Path First (OSPF)?
Routing Algorithms (Distance Vector, Link State) and BGP/OSPF
GATE CS 2014 Set 2, Q.34 (CS Q.24)
Which one of the following socket API functions converts an unconnected active TCP socket into a passive socket?
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2014 Set 2, Q.35 (CS Q.25)
In the diagram shown below, L1 is an Ethernet LAN and L2 is a Token-Ring LAN. An IP packet originates from sender S and traverses to R, as shown. The links within each ISP and a...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2014 Set 2, Q.36 (CS Q.26)
Consider the store and forward packet switched network given below. Assume that the bandwidth of each link is bytes / sec. A user on host A sends a file of size by...
Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2014 Set 2, Q.37 (CS Q.27)
An IP machine Q has a path to another IP machine H via three IP routers R1, R2, and R3. H acts as an HTTP server, and Q conne...
OSI/TCP-IP Layering, Physical Layer and Switching
GATE CS 2014 Set 2, Q.38 (CS Q.28)
A graphical HTML browser resident at a network client machine Q accesses a static HTML webpage from a HTTP server S. The static HTML page has exactly one static embedded image w...
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2014 Set 3, Q.33 (CS Q.23)
In the following pairs of OSI protocol layer/sub-layer and its functionality, the INCORRECT pair is
OSI/TCP-IP Layering, Physical Layer and Switching
GATE CS 2014 Set 3, Q.34 (CS Q.24)
A bit-stuffing based framing protocol uses an 8-bit delimiter pattern of 01111110. If the output bit-string after stuffing is 01111100101, then the input bit-string is
Data Link Layer: Framing, Error Detection and Sliding Window
GATE CS 2014 Set 3, Q.35 (CS Q.25)
Host A (on TCP/IP v4 network A) sends an IP datagram D to host B (also on TCP/IP v4 network B). Assume that no error occurred during the transmission of D. When D reaches B, whi...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2014 Set 3, Q.36 (CS Q.26)
An IP router implementing Classless Inter-domain Routing (CIDR) receives a packet with address 131.23.151.76. The router's routing table has the following entries: Prefix | Outp...
Routing Algorithms (Distance Vector, Link State) and BGP/OSPF
GATE CS 2014 Set 3, Q.37 (CS Q.27)
Every host in an IPv4 network has a 1-second resolution real-time clock with battery backup. Each host needs to generate up to 1000 unique identifiers per second. Assume that ea...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2014 Set 3, Q.38 (CS Q.28)
An IP router with a Maximum Transmission Unit (MTU) of 1500 bytes has received an IP packet of size 4404 bytes with an IP header of length 20 bytes. The values of the relevant f...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2013, Q.12 (CS Q.12)
The transport layer protocols used for real time multimedia, file transfer, DNS and email, respectively are
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2013, Q.13 (CS Q.13)
Using public key cryptography, X adds a digital signature to message , encrypts , and sends it to Y, where it is decrypted. Which one of t...
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2013, Q.14 (CS Q.14)
Assume that source S and destination D are connected through two intermediate routers labeled R. Determine how many times each packet has to visit the network layer and the data...
OSI/TCP-IP Layering, Physical Layer and Switching
GATE CS 2013, Q.36 (CS Q.36)
Determine the maximum length of the cable (in km) for transmitting data at a rate of 500 Mbps in an Ethernet LAN with frames of size 10,000 bits. Assume the signal speed in the...
Medium Access Control (ALOHA, CSMA/CD) and Ethernet/Switching
GATE CS 2013, Q.37 (CS Q.37)
In an IPv4 datagram, the M bit is 0, the value of HLEN is 10, the value of total length is 400 and the fragment offset value is 300. The position of the datagram, the sequence n...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2012, Q.10 (CS Q.10)
The protocol data unit (PDU) for the application layer in the Internet stack is
OSI/TCP-IP Layering, Physical Layer and Switching
GATE CS 2012, Q.22 (CS Q.22)
Which of the following transport layer protocols is used to support electronic mail?
Application Layer: DNS, HTTP, SMTP, FTP · Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2012, Q.23 (CS Q.23)
In the IPv4 addressing format, the number of networks allowed under Class C addresses is
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2012, Q.34 (CS Q.34)
An Internet Service Provider (ISP) has the following chunk of CIDR-based IP addresses available with it: 245.248.128.0/20. The ISP wants to give half of this chunk of addresses...
IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT · IPv4/IPv6 Addressing, Subnetting, CIDR, ARP, ICMP and NAT
GATE CS 2012, Q.44 (CS Q.44)
Consider a source computer () transmitting a file of size bits to a destination computer () over a network of two routers ( and ) and three links (,...
OSI/TCP-IP Layering, Physical Layer and Switching
GATE CS 2012, Q.45 (CS Q.45)
Consider an instance of TCP's Additive Increase Multiplicative Decrease (AIMD) algorithm where the window size at the start of the slow start phase is 2 MSS and the threshold at...
Transport Layer: UDP, TCP Flow and Congestion Control, Sockets
GATE CS 2011, Q.2 (CS Q.2)
A layer-4 firewall (a device that can look at all protocol headers up to the transport layer) CANNOT
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2011, Q.4 (CS Q.4)
Consider different activities related to email. : Send an email from a mail client to a mail server : Download an email from mailbox server to a mail client : Che...
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2011, Q.9 (CS Q.9)
HTML (HyperText Markup Language) has language elements which permit certain actions other than describing the structure of the web document. Which one of the following actions i...
Application Layer: DNS, HTTP, SMTP, FTP
GATE CS 2011, Q.52 (CS Q.52)
The cost of link N2-N3 reduces to 2 (in both directions). After the next round of updates, what will be the new distance vector at node, N3?
Routing Algorithms (Distance Vector, Link State) and BGP/OSPF
GATE CS 2011, Q.53 (CS Q.53)
After the update in the previous question, the link N1-N2 goes down. N2 will reflect this change immediately in its distance vector as cost, . After the NEXT ROUND of up...
Routing Algorithms (Distance Vector, Link State) and BGP/OSPF