Computer Network Principles - Revision Exam Paper

ANGLIA RUSKIN UNIVERSITY

FACULTY OF SCIENCE AND TECHNOLOGY

DEPARTMENT OF COMPUTING & TECHNOLOGY

REVISION EXAMINATION PAPER

EJ230001S/DEJ330004S

COMPUTER NETWORK PRINCIPLES

TIME ALLOWED: 1 HOUR & 30 MINUTES

INSTRUCTIONS TO CANDIDATES:

1. ANSWER ALL QUESTIONS2. MARKS WILL BE AWARDED FOR EACH CORRECT ANSWER3. NO MARKS WILL BE AWARDED TO A QUESTION WITH MORE

THAN THE CORRECT NUMBER OF ANSWERS

Materials Permitted in the Examination:

1. NONE

Mitigation – Academic regulations 6.81 - 6.946.87 Claims for mitigation must be submitted by the student or in exceptional

circumstances (e.g. when a student has been hospitalised) by a Director of Studies, Programme Leader or Student Adviser on behalf of the student no later than five working days after the date on which an examination has been sat.

Number of questions set: 40

Number of pages: 18 (including cover)

Name of examiner/tutor: MIKE SMITH

Page 1 of 18

1. Which OSI layer manages data segments?

a) Application Layerb) Presentation Layerc) Session Layerd) Transport Layer

[2 marks]

2. How does the Transport layer allow a host to maintain multiple, simultaneous communication streams across different applications?

a) It uses error control mechanismsb) It uses a connectionless protocol only for multiple simultaneous

transmissionsc) It uses multiple Layer 2 source addressesd) It uses multiple ports

[2 marks]

3. Which three statements ate true about network layer addressing?

a) It uses the last octet of the IP address to identify the networkb) It supports data communications between networksc) It is configured by a network techniciand) It is a 16-bit IPv4 addresse) It prevents broadcastsf) It uniquely identifies each host

[max 3 marks]

Page 2 of 18

4. Refer to the above exhibit.

A PC is connected to a network. Which action will verify that the PC can communicate with its default gateway?

a) Use the ping 127.0.0.1 commandb) Use the ipconfig commandc) Use the ipconfig/all commandd) Use the ping 10.0.0.254 command

[2 marks]

5. Which two types of media can provide up to 1Gbps?

a) 10 BASE-Tb) 100 BASE-Tc) 100 BASE-FXd) 1000 BASE-TXe) 1000 BASE-SX

[Max 2 marks]

Page 3 of 18

6.

The diagram above represents the process of sending email between clients.

Which list correctly identifies the component or protocol used at each numbered stage of the diagram?

a) 1.MUA 2.MDA 3.MTA 4.SMTP 5.MTA 6.POP 7.MDA 8.MUAb) 1.MUA 2.POP 3.MDA 4.SMTP 5.MTA 6.MDA 7.SMTP 8.MUAc) 1.MUA 2.POP 3.SMTP 4.MDA 5.MTA 6.SMTP 7.POP 8.MUAd) 1.MUA 2.SMTP 3.MTA 4.SMTP 5.MTA 6.MDA 7.POP 8.MUA

[2 marks]

7. Refer to the exhibit.

The router of the company had failed and was replaced. After the replacement hosts C and D in the Education office are able to ping each other, but they are unable to access the hosts in the Accounts office. What is the likely cause of the problem?

a) The IP address at the fa0/0 interface of the router is incorrectly configuredb) The subnet mask at the fa0/1 interface of the router is incorrectly enteredc) The IP address at the serial interface of the router is incorrectly configuredd) The hosts in the Accounts office are not on the same subnet as the hosts in

the Education office

[2 marks]

Page 4 of 18

8. Which three statements are true about transport layer protocols?

a) The UDP transport layer protocol provides for low overhead data delivery

b) The TCP transport layer protocol uses windowing and acknowledgements for reliable transfer of data

c) The TCP and UDP ports numbers are used by application layer protocols

d) The TCP transport layer protocol provides services to direct the data packets to their destination hosts

e) The UDP transport layer protocol is a connection-oriented protocolf) The UDP transport layer protocol keeps track of the data segments in

each conversation

[max 3 marks]

9. Which OSI layer uses the header information to reassemble the data segments into streams?

a) Application layerb) Network layerc) Presentation layerd) Session layere) Transport layer

[2 marks]

Page 5 of 18

10. Refer to the exhibit.

The host was disconnected from Switch 2 and connected to Switch 1. Which combination of IP address subnet mask and default gateway should be assigned to this host to allow it to function in the network?

a) IP Addr: 10.0.9.37 Mask: 255.255.255.240 Gateway 10.10.9.35b) IP Addr: 10.0.9.37 Mask: 255.255.255.224 Gateway 10.10.9.35c) IP Addr: 10.0.9.29 Mask: 255.255.255.248 Gateway 10.10.9.35d) IP Addr: 10.0.9.32 Mask: 255.255.255.224 Gateway 10.10.9.35e) IP Addr: 10.0.9.37 Mask: 255.255.255.224 Gateway 196.1.105.6f) IP Addr: 10.0.9.63 Mask: 255.255.255.224 Gateway 10.10.9.35

[2 marks]

11. Which subnet will allow 2040 hosts per subnet on the IP network 10.0.0.0?

a) 255.255.0.0b) 255.255.254.0c) 255.255.252.0d) 255.255.248.0e) 255.255.240.0f) 255.255.255.128

[2 marks]

12. What are the three characteristics of CSMA/CD?

a) Devices listen to the media and transmit data only when they cannot detect another signal on the media

b) All devices on the media can hear all communicationsc) Devices communicate based on a configured priorityd) After a collision occurs, the devices that caused the collision have first

priority when attempting to retransmite) When a collision occurs, all devices stop transmitting for a randomly

generated period of timef) CSMA/CD uses a token system to avoid collisions

[max 3 marks]

Page 6 of 18

13. Which three addresses belong to the category of private IP addresses?

a) 10.0.0.1b) 127.0.0.1c) 150.0.0.1d) 172.16.0.1e) 192.168.0.1f) 200.100.50.1

[max 3 marks]

14. An organisation has decided to use IP addresses in the range: 172.20.128.0 to 172.20.143.255. Which combination of Network ID and Subnet mask identifies all IP addresses in this range?

a) Network ID: 172.20.128.0 Mask: 255.255.255.0b) Network ID: 172.20.128.0 Mask: 255.255.0.0c) Network ID: 172.20.128.0 Mask: 255.255.224.0d) Network ID: 172.20.128.0 Mask: 255.255.240.0e) Network ID: 172.20.128.0 Mask: 255.255.255.240

[2 marks]

15. What are the two characteristics of the data link layer?

a) It segments and reorders the datab) It exchanges the frames between nodesc) It defines the method by which network devices place data onto the

mediad) It manages the transfer of data between the processes thar run on each

hoste) It retrieves signals from the media and restores them to their bit

representations

[max 2 marks]

Page 7 of 18

16. Refer to the exhibit

.

Host A wants to connect to Host B on a different network. Which three IP addresses can be assigned to Host A to enable this connectivity?

a) 172.16.11.36b) 172.16.11.95c) 172.16.11.88d) 172.16.11.70e) 172.16.11.64f) 172.16.11.67

[max 3 marks]

Page 8 of 18

17. Refer to the exhibit

Host A attempts to establish a TCP/IP session with Host C. During this attempt, a frame was captured at the FastEthernet Interface fa0/1 of Router Y. The packet inside the captured frame has the IP source address 172.16.1.5 and the destination address is 172.16.7.24.

What is the source MAC address of the frame at the time of capture?

a) 0040.8596.DE82b) 0060.7320.B826c) 0060.7320.D632d) 0010.4F74.AC99e) 0040.8596.DE81

[2 marks]

Page 9 of 18

18. Refer to the exhibit.

Host A and Host B are unable to communicate with each other. What is the reason for this?

a) Host A is assigned a network addressb) Host B is assigned a multicast addressc) Host A and Host B belong to different hostsd) The gateway addresses are network addresses

[2 marks]

19. Refer to the exhibit.

10.0.0.24 is subnetted, 1 subnetsR 10.1.1.0 [120/1] via 172.16.1.4, 00:00:05, FastEthernet0/0172.16.10.0/24 is subnetted, 1 subnetsR 172.16.10.0 [120/1] via 172.16.2.9, 00:00:05, FastEthernet0/1172.16.1.0/24 is subnetted, 1 subnetsC 172.16.1.0 is directly connected, FastEthernet0/0172.16.2.0/24 is subnetted, 1 subnetsC 172.16.2.0 is directly connected, FastEthernet0/1S* 0.0.0.0/0 (1/0) via 172.16.1.4

A router, the table of which is shown, receives a packet that is destined for 192.168.9.4. How will the router treat the packet?

a) It will drop the packetb) It will forward the packet via FastEthernet 0/1c) It will forward the packet to the next hop addressd) It will forward to 172.16.2.0

[2 marks]

Page 10 of 18

20. Refer to the exhibit.

Which two facts can be determined about the topology?

a) Four collision domains are presentb) One logical network is representedc) Two broadcast domains are presentd) Three networks are needede) Three logical address ranges are required

[max 2 marks]

Page 11 of 18

21. Which two statements are true about classless routing protocols?

a) They can be used for discontiguous networksb) They can forward supernet routes in routing updatesc) They cannot implement classful routes in routing tablesd) They use only a hop count metrice) They do not include the subnet mask in routing updates

[max 2 marks]

22. Which two statements are true for OSPF Hello packets?

a) They are used for dynamic neighbour discoveryb) They are used to maintain neighbour relationshipsc) They are used to determine the complete network topologyd) They are used with timers to elect the designated router with the fastest

linke) They are used to negotiate correct parameters among neighbour

interfaces

[max 2 marks]

23. Which three statements are true regarding the encapsulation and de-encapsulation of packets when travelling through a router?

a) The router modifies the TTL field, decrementing it by oneb) The router changes the source IP to the IP of the exit interfacec) The router maintains the same source and destination IPd) The router changes the source physical address to the physical address

of the exit interfacee) The router changes the destination IP to the IP of the exit interfacef) The router sends the packet out of all other interfaces, besides the one

it entered the router on

[max 3 marks]

24. Which two situations require the use of a link-state protocol?

a) Fast convergence of the network is criticalb) The network is very largec) The network administrator has limited knowledge to configure and

troubleshoot routing protocolsd) The network is a flat networke) The capacity of the router is low

[max 2 marks]

Page 12 of 18

25. In a complex lab test environment, a router has discovered four paths to 192.168.1.0/24 via the use of the RIP routing process. Which router will be installed in the routing table after the discovery of all four paths?

a) R 192.168.1.0/24 [120/3] via 192.168.110.1, 00:00:17, Serial0/1/0b) R 192.168.1.0/24 [120/2] via 192.168.200.1, 00:00:17, Serial0/0/0c) R 192.168.1.0/24 [120/1] via 192.168.100.1, 00:00:17, Serial0/0/1d) R 192.168.1.0/24 [120/4] via 192.168.101.1, 00:00:17, Serial0/1/1

[2 marks]

26. What are two tasks that must be completed before two routers can use OSPF to form a neighbour adjacency?

a) The routers must elect a designated routerb) The routers must agree on the network typec) The routers must use the same dead intervald) The routers must exchange link state requestse) The routers must exchange database description packets

[2 marks]

27. What are two functions of a router?

a) It connects multiple IP networksb) It controls the flow of data via the use of Layer 2 addressesc) It determines the best path to send packetsd) It manages the VLAN databasee) It increases the size of the broadcast domain

[max 2 marks]

28. Refer to exhibit.

A network administrator adds this command to router R1:

ip route 192.168.2.0 255.255.255.0 s0/0/0

What is the result of adding this command?

a) This route is automatically propagated throughout the networkb) The traffic for network 172.16.1.0 is forwarded to network 192.168.2.0c) A static route is establishedd) The traffic for all Class C networks is forwarded to 172.16.1.2

[2 marks]

Page 13 of 18

29. Refer to the exhibit.

All routers are properly configured with default configurations and running the OSPF protocol. A host on the 192.168.3.0/24 network is communicating with a host on the 192.168.2.0/24 network.

Which path will be used to transmit the data?

a) The data will be transmitted via R3-R2b) The data will be transmitted via R3-R1-R2c) The traffic will be load balanced between two paths – one via R3-R2

and the other via R3-R1-R2d) The data will be transmitted via R3-R2, and the other path via R3-R1-

R2 will be retained as a backup path

[2 marks]

30. A router that uses the RIP routing protocol has an entry for a network in the routing table. It then receives an update with another entry for the same network but with a lower hop count. What action will the router take for this new update?

a) It will append the update information to the routing tableb) It will invalidate the entry for that network in the routing tablec) It will replace the existing routing table entry with the new

informationd) It will ignore the update

[2 marks]

Page 14 of 18

31. Refer to the exhibit

All routers are configured to run RIPv1 and are fully converged. Which routing updates will be received by R3?

a) updates for 192.168.1.0/24 and 192.168.2.0/24b) updates for 172.16.2.0/24 and 172.16.3.0/24c) updates for 172.16.1.0/24, 172.16.2.0/24 and 172.16.3.0/24d) updates for 172.16.0.0/16

[2 marks]

32. Refer to the exhibit

What summarisation should R2 use to advertise its LAN networks to R1?

a) 172.16.0.0/24b) 172.16.4.0/22c) 172.16.4.0/23d) 172.16.4.0/24

[2 marks]

33. Two routers need to be configured within a single OSPF area. Which two components need to be configured on both routers to achieve this?

a) the same process IDb) the same area IDc) network addresses and wildcard masksd) the same router IDe) the same loopback address

[max 2 marks]

Page 15 of 18

34. Refer to the exhibit:

All routers are configured for OSPF area 0. The network administrator requires that R2 always be the DR and maintain adjacency.

Which two configurations can achieve this?

a) Change the OSPF area of R2 to a higher valueb) Change the router ID for R2 by assigning the IP address

172.16.30.5/24 to the Fa0/0 interfacec) Change the priority values of the Fa0/0 interfaces of R1 and R3 to 0d) Configure a loopback interface on R2, with an IP address higher than

any IP address on the other routerse) Configure R1 and R3 with an IP address whose value is higher than

that of R2

[max 2 marks]

35. Refer to the exhibit:

All routes are advertised and fully operational on all routers. Which statement is true about the path that the data will take from router A to router B?

a) If EIGRP is used with default configurations, the data will be equally distributed between the two paths – A, D, B and A, C, B

b) If RIPv1 is used with default configurations, the data will be load-balanced on all paths

c) If EIGRP and OSPF are both used with default configurations, the data will be sent through paths learned by the OSPF protocol

d) If RIPv2 is used with default configurations, the data will be equally distributed between the two paths – A, D, B and A, C, B

[2 marks]

Page 16 of 18

36. Which mechanism helps to avoid routing loops by advertising a metric of infinity?

a) route poisoningb) split horizonc) hold-down timerd) triggered updates

[2 marks]

37. Refer to the exhibit:

Host A is unable to access the Internet, and troubleshooting has revealed that this is due to an addressing problem. What is incorrectly configured in this network?

a) the IP address of the Fa0/0 interface of R1b) the subnet mask of the s0/0/0 interface of R1c) the IP the address of the s0/0/0 interface of R1d) the subnet mask of the s0/0/0 interface of R2

[2 marks]

38. Refer to the exhibit:

The command ip route 0.0.0.0 0.0.0.0 s0/0/0 is run on router R2. What are the two results of this command?

a) A static route will be updated in the routing tableb) The traffic from the Internet will be directed to R2c) The traffic from the source network 172.16.0.0/22 will be blockedd) The route will be specified as the default route for all networks not

defined in the routing tablee) All the broadcasts will be forwarded via the s0/0/0 interface of R2

[max 2 marks]

Page 17 of 18

39. Refer to the exhibit:

Gateway of last resort is 192.168.2.1 to network 0.0.0.010.0.0.0/24 is subnetted, 3 subnetsC 10.0.1.0 is directly connected, FastEthernet0/0C 10.0.2.0 is directly connected, Serial0/0/0R 10.0.3.0 [120/1] via 10.0.2.2, 00:05:01, Serial0/0/0R 192.168.0.0/24 [120/2] via 10.2.2.2, 00:03:50, Serial0/0/0C 192.168.1.0/24 is directly connected, FastEthernet0/1C 192.168.2.0/24 is directly connected, Serial0/0/1S* 0.0.0.0/0 is directly connected, Serial0/0/1

The router receives a packet that is destined for 192.168.5.79. How will the router handle this packet?

a) It will forward the packet via the FastEthernet 0/0 interfaceb) It will forward the packet via the Serial 0/0/0 interfacec) It will forward the packet via the Serial 0/0/1 interfaced) It will drop the packet

[2 marks]

40. Refer to the exhibit:

A device is required to complete the connection between router R1 and the WAN. Which two devices can be used for this?

a) a CSU/DSU deviceb) a modemc) an Ethernet switchd) a hube) a bridge

[max 2 marks]

Page 18 of 18