Computer Networks Answers

Which one of the following is correct?

a. In IP broadcasting, the message is delivered to all hosts on the same subnet

b. In IP broadcasting, the message is delivered to most hosts on all subnets

c. In IP broadcasting, the message is delivered to all hosts on most subnets

d. In IP broadcasting, the message is delivered to all hosts on all subnets

Which of the following is correct as part of DDos-attack (shown in class) ?

a. sysctrl -w net.ipv4.tcp_syncookies=0

b. syscopy -w net.ipv4.tcp_syncookies=0

c. syscmd -w net.ipv4.tcp_syncookies=0

d. sysctl -w net.ipv4.tcp_syncookies=0 

What unique address is embedded in an Ethernet NIC and used for communication on an Ethernet network?

a. Host address

b. IP address

c. Network address.

d. MAC address

Which command can be used to make socket programming between two computers that are attached to the same network (shown in class) ?

a. connectionSocket, addr = serverSocket.send()

b. connectionSocket, addr = serverSocket.accept()

c. connectionSocket, addr = serverSocket.reject()

d. connectionSocket, addr = serverSocket.receive()

Briefly describe the following terms implemented in network security. (9 marks)

a Confidentiality (3)

b Authentication (3)

c Message Integrity (3)

Name one wireshark-filtering-command to show the tcp and http packets sent to ip address 65.208.228.223;

b) Name one UNIX/LINUX-command to check which port of your computer is listening

c) Name one python-command to receive a packet using a server socket.

d) Name one UNIX/LINUX-command to implement CIDA subnet mask x.x.x.x/23 on interface enp3 

Describe the differences between a symmetric key encryption system and a public key encryption system. Name one algorithm or application for each system. (10 marks)

What is ICANN, and give 2 major functions of ICANN.

b) What is/are used (in datagram) to direct segment to appropriate socket of your target computer.

Give 2 types of Cyber attack using malware

b) Give 2 prevention methods to avoid man-in-the-middle-attack

A new company has three buildings and each building is more than 100 m apart from the other. A backbone network is to be installed to connect the buildings together. A fiber-optic backbone is proposed. (9 marks)

Discuss whether the following results can be achieved by this proposal.

(i) The network must operate at a speed of at least 200 Mbps (3%)

(ii) The network should be secured from eavesdropping (3%)

(iii) The budget should be less expensive than coaxial-cable (3%)