Computer Network

1. 1
Contents
Task 1: Network Infrastructure and Protocols ………………………………………………
Error! Bookmark not defined.
Task 2: Addressing……………………………………………………………………………………………………………..6
Task 3: Security ………………………………………………………………………………….11
Task 4: Diagram and explanation …………………………………………………………….13
Task 5: Remote access …………………………………………………………………………16

2. 2
A) Different between newer versions of Ethernet, and Wi-Fi and a
recommendation about the technology the company should use.
Criteria Fast
Ethernet(1
00base-TX)
Gigabit
Ethernet(1
000BASE-
T)
10 Gigabit
Ethernet(10
base-T)
WI-FI 10base T
Cable type It uses 5e
(fiber optic
and UTP
cable)
It uses 5e
(fiber optic
cable)
It is based
(it uses
concerning
cable type)
on cat 6a
cat 6 (fiber
optic)
It uses
wireless
system.
It uses cat 5
UPP for
cabling
Data rate Delivers
100
megabit per
seconds
Delivers 1
gigabit per
seconds
Delivers 10
gigabit per
seconds
It delivers
speeds
range from
433 Mbps
(megabits
per second)
up to
several
gigabits per
seconds
Delivers 10
megabit per
seconds
Network
contention
It has lower
speed than
the higher
categories
The
Internet is a
bottleneck,
faster
cables
won't help.
The Internet
is a
bottleneck,
faster
cables won't
help.
Has
interference
(‘signal
interference
’) which ca
e use to
connect
smart
phone,
tablet etc.
has high
electrical
interference
Recommendation
I advise to keep the network in the company as wired because WIFI has more high
interference and less secure.
COMPUTER NETWORKS
Task 1: Network Infrastructure and Protocols

3. 3
Concerning their smart device, I recommend that the company should have a
separate wireless network as a guest. The most essential aspect of the LAN network
is that, their network would be more convenient if they upgrade to cat 5e version of
the Ethernet.
B) Below Differentiate between physical network device on the network. On where
it operate on the OSI model.
A Hub
It a physical network device that has multiple ports to connect different device on
the internal network. Hubs are not intelligent as compare to other network
swishes because it does not have any intelligent as to where a data packet
supposed to be send. For instance, when a packet arrives at one of it port. It will
send to all other port. Hub works at layer 1. That is, physical layer of the OSI
model that actas transmission of data.
A SWITCH
It is a network device with multiple port connections, that accept internal
connections from devices (network devices) such as PCs, servers etc. unlike
a hubs, which are not smart. A switch actually learns the physical addresses
(that is, MAC address) which will be connected to it. So when a data packet
arrives it its port, it only direct to the intended destination port. Switch works
at layer 2, to process/forward data. (“Data link layer”). (Christensson, 2014)
Wireless Access Point
It is a physical network device used to establish a wired-to-wireless
connection. Wireless access point operate at the layer 2 (“Physical layer”) of
the OSI model for the transmission of packet between nodes. (Mitchell, 2019)
Routers

4. 4
They are physical networks devices on the network, that enable several
network devices to be exchange information based on their IP address.
Router makes the wireless device to access LAN network. Routers are very
intelligent because when it receives packets, it checks the IP address on the
device, and forward it to the intended destination. Router works at the network
layer (“layer 3”) of the OSI model managing the network. (Mitchell, 2019)
C) Purpose of the OSI model.
Application layer (layer 7)
 It provides services for network application such as Firefox
Chrome etc to exchange data over the network that enable the
user to interact with the application. (Bahl, 2018)
Presentation layer (layer 6)
 It receives data from application layer. This data is in a form of
characters/numbers, so the application layer converts these
numbers to the understanding of machine such as 0s/1s.
Presentation layer reduces the size of the data before it
transmitted to its original size (“data compression”). These help
data to be transmitted in a very high speed. Also presentation
layer handles encryption and decryption. (Bahl, 2018)
Session layer (layer 5)
 It is a layer that deals with communication. Session layer helps
in managing connections enabling sending and receiving data
and also termination of session. Session layer provides session
support such as NETBIOS (“Network Basic Input/output
System”) which allows application on different computers to
communicate to each other, Apple Talk Session Protocol (ASP)
etc. (Bahl, 2018)
Transport layer (layer 4).
 This is to ensure successful data is delivered includes checking
for errors and lost/duplicated frames. On the internet, it offers
traffic control and message recognition, such as TCP

5. 5
(Transmission Control Protocol), UDB (User Datagram Protocol)
etc. (Moran, 2015)
Network layer (layer 3).
 This layer is where routers operate. It is in charge of managing
the logical address and controls how the subnet operates.
These help packets to be delivered to their intended destination.
Internet Protocol (IP) is one the example. (Bahl, 2018)
Data link layer (layer 2).
 It provide means of transferring data from one computer to
another via local media such as optical Fibber, LAN cable, Air
etc. It handles traffic control links and terminates frames, etc.
ATM, ARP, FDDI etc. are example protocols. (Bahl, 2018)
Physical layer (layer 1)
 This layer is where willing occurs. Physical stuffs that connect
computers together. It covers verity of medium devices including
repeaters, connectors, cabling etc. (Bahl, 2018)
D) Purpose of SEVEN (7) protocols.
i. TCP abbreviation stand for Transmission Control Protocol. It’s a
“connection-oriented protocol” which guarantees available data transfer,
when it detects data segment drops in a network, the lost/dropped
network will be transmitted. Therefore, sender will determine the
success of transmission following the acceptance of the segment it
receives on the basis of an acknowledgement from the recipient. On the
OSI model TCP works in transport layer. (Rouse, August)
ii. File Transfer Protocol (FTP). It is set of protocol ‘rules’ (TCP/IP) which
provide facilities that enable the user to upload and download files over
the server. FTP receives and sends data in an unscripted format
between the recipient and the sender, making them unsure and more
reverent for attacks. FTP works at Application Layer. (Margaret, 2015)

6. 6
iii. Hyper Text Transfer Protocol Secure (HTTPS). It a protocol that
encrypts data/communication (sending data and receiving) over the
network. It operates at the Application layer. (Hoffman, 2018)
iv. ISDN (Integrated Services for Digital Network).It is a set of standard
for communication that ensures that, voices, videos etc. are transmitted
simultaneously over the internet. On the OSI model it operate in the
physical layer (Margaret, 2016).
v. AFP (Apple Talk Filling Protocol). It a client protocol of the Mac OS
file that permits users to access external system files. AFP offers
security features which ensure that user do not access into a certain
data. It operate at the Presentation Layer of the OSI model. (Techopedi,
2019)
vi. TLS (Transport Layer Security).It a protocol designed to encrypt
communication between applications. It works at the Session Layer.
(Kerravala, 2019)
vii. ARP (Address Resolution Protocol). It is a protocol, that resolves an
IP address to media address to be recognise in the LAN. It operates at
the network layer (Rouse, 2019)
a.
Reasons network need addressing
Addresses are very important in network component basically because to allow
devices to communicate over the network. For example, if there are two PCs on a
LAN (Local Area Network) and if PC1 want to send a request to PC2. The one
sending the request will use the IP address of the other network to locate it.
MAC ADDRESS
Task 2: Addressing.
Different between MAC address and an IP address.

7. 7
 It is a physical unique address on the network. The address is
assigned to the NIC card by the manufacturer.It consists of 48-bit
hexadecimal which cannot be change or reset and has 48 bit layer 2
within LAN. (NETGEAR, 2018)
IP ADDRESS
 Internet Protocol address is dynamic address that is used to assign on
Local Area Network to defines the connection between different
computers on the same network. IP address is uniquely assigned via
Dynamic Host Configuration Protocol (DHCP). The administrator
assigns the IP addresses, and also be static. (IP Location Logo, 2018)
IPv4
 IPv4 has 32-bit address space.
 IPV4 are required to be able to reassemble a packet size of 576 bytes
(fragmentation optional).
 It has 4 division block.
IPv6
 With IPv6, it uses 128-bit address space.
 In IPv6 data fragmentation and reassembly are not handled by the
router. Fragmentation is performed at the destination host.
 It has 8 division blocks.
b.
Difference between a private IPv4 address and a public IPv4 address
Private IPv4 address
 Private IP is designed use unique IP number to allow two or more
computers to exchange data on LAN (Local Area Network)
network.Network devices, such as routers, use Network Address
Translation (NAT) to provide private IP addresses. Private IP address
cannot be connected to the internet directly. This provides security
area to the network. For instance, a network NAT device uses ISP to
Difference between IPv4 and IPv6

8. 8
communicate with the Internet and check whether incoming data was
sent from the private IP computer assign to. If not, it will reject it. (IP
Location Logo, 2018)
Public IPv4 address
 A public IP address are required to be access the internet. For a device
to connect to the web, it must have a unique IP for it to be easily
locating the internet and allow other nodes and device to connect. It is
usually assigned to the web server, email server etc. (IP Location
Logo, 2018)
Private IP address ranges.
c. DHCP
DHCP
 It is a client/server protocol that automatically provides IP address to
devices on the LAN (Local Area Network) so that the device can
exchange data using IP.DHCP is generally used for the configuration of
device subnet mask, default gateway and DNS servers. It has been
defined by RFCs 2131 and 2132 as IETF (Internet Engineering Task
Force), based on Bootstrap Protocol (BOOTP). (Rouse M. ,
SearchNetworking, 2017)
Where DHCP is located and why it will be used.
 In the IT centre network, DHCP would be in the router that gives out
the LAN addresses to IP’s on the same subnet.
 In the remote office it can be used to configure the RRAS server to
allocate IP addresses to remote clients from a static range of IP
addresses, by relaying client to the DHCP server for address allocation
Class Address Range Subnet Mask
A 10.0.0.0 to
10.255.255.255
255.0.0.0
B 172.16.0.0 to
172.31.255.255
255.240.0.0
C 192.168.0.0 to
192.168.255.255
255.255.0.0

9. 9
Why use DHCP?
 Efficiency. It is makes it easy when configuring than configuring each
node/host manually (statically).
 Simplicity. DHCP offers the capability to assign/manage several
parameters required on the network this include, subnet mask, default
gateway DNS servers etc.
d. ARP
ARP
Address Resolution Protocol (ARP). It a protocol that is used to
detect/discover the link layer address that is, MAC address.
Why is ARP needed?
ARP is needed because it enable computers to communicate using
Ethernet addresses. For instance, assuming there are two computers
within a network with IP address 1 and 5, and if computer with address
1 want to speak to computer with address 5. Both machine uses ARP
in order to communicate. Concerning IP routing, ARP identifies the
hardware address (MAC) of a host that is known from its IP address
and maintains a cache (table) where the MAC address is mapped to IP
addresses.
e. Default Gateway and Subnet Mask
A default gateway
 A default gateway provides access point or IP based computers uses to
transmit data to a device in another network/the internet. It is the exit point on
the local network that handles outgoing network connections.

10. 10
Reasons Default gateway is required.
 Default gateway is needed because it helps IP enable device to share data to
each other outside the network (communication with the subnet). It has a local
network exit point that control outgoing network connections.
Subnet mark
 Subnet mark is used is used to determine one side of the address that the
network uses and another side that the host uses. It uses 32bite that mark up
the IP address. It is made of 0’s (network bit) and 1’s (host bit).
 Reasons why subnet mark is required are below:
I. To allow device different device to communicate to each other on the
network.
II. It offers security factors because it avoids devices such as computers
to communicating on other networks.
III. It helps to provide limitation to IP address on the network.
f. IP Routing Table
Routing table consist of rules which is in a form of table format that is used
to identify where data packet travels via the IP (internet protocol). IP
routing table is used by all enable IP devices. Routing table is made of IP
addresses on distinctive device that help to determines how to reach each
device on the same network. It is predefined patch, used to transmit
packets. On the routing table, router preforms a function as database that
keeps all the IP addresses of the linked computers. When a package
reaches to the router, it sends the package to where the it belongs using
the IP. (Rouse, Searchnetworking, 2007)

11. 11
Task 3: Security
a. Measures to be taken to keep the network safe
a) Firewall filtering. I recommend that, firewall to be install to prevent
internal/external threats and other domestic behaviour.

12. 12
b) Installingantivirus and anti-malware software. I recommend that this
software should be installed to avoid threat suchmalwares and
spywares and also to improve the device performance.
c) MAC addresses filtering. This will help to define and connect devices to
the network even if the password appears unknown.
d) Security access. It ensures that network component and applications
necessary for the work are accessible to users only.
e) Sub-netting. This will be good method to safeguard information
travelling from one section of the employee to another part since there
are logically divided.
f) VPN. Assigning to this will guarantee that our network are not tracked
and captured. VPN will tunnel our activities online via various servers
to ensure our sensitive information are safe.
g) Maintenance. In order to maintain a good working environment for the
business requires regular maintenance forhardware and software’s.
This should be carried out because of software containing flaws and
old hardware. Regular upgrade will add new security features to the
system.
b. Biggest threat
In my opinion, the greatest threat to the system is spyware and virus
because someone might affect the systems with spyware, to purposely
truck information over the internet. Someone who captures internal
business activity would be regarded as a significant problem. Spyware
can get access to all activities that occur over the network. For
example, spyware can edit/retype information transmitting to a
particular network, it can also redirects webpage and pop-up ads from
flood screen. Spyware can change user’s configuration and can send
viruses that can crash the system.

13. 13
Task 4: Diagramand explanation
a.
s

14. 14
b. IP address allocation table.
c. Hardware Components
- Firewall. Since there shouldn’t be any case of threat issues, this
will provide service that will help to remove every threat.
- Router. It will help to join different network component together,
and for the reason, it will be use to connect LAN with the
network.
- Sever. They hold document in the cloud. It offers service that
allow data and file to be exchange over the network. Therefore,
this will be adopted to allow files and other document to be sent
over the network
- During cabling lining, shielded twisted pair was used since we
want we went clear communication over the internet. unlike the
unshielded which is more prone to noise.

15. 15
- Switches. It has a multi-port connection that connect different
devices. Switches was used since devices(router, computer,
server) need to communicate to each other.
d. Prices and specification of suitable hardware/ software
Devices Details Specification Price
PCs Toshiba C5d - CPU type. Intel i3
- Display graphic. HD
Graphics.
- RAM: 8GB.
- Storage: 512 HDD.
- Connectivity: Gigabit
Ethernet
£290.00
Server
used
Dell Edge
Power 30
- CPU: Intel Xon E3-125
v2.
- RAM: 50GB.
- Uses six SATA HDD.
- Connectivitytype: 10 x
USB ports, HDMI,
DisplayPort, VGA etc.
£ 495.00
Router NETGEAR
R800
Nigthawk X3
Tri-Band
A3200
- Speed (3.2 Gbps).
- 1 GHz dual core
processor.
- Handle 200 users
£149.99
Firewall Zyxel ZyWALL - More secure and have
upgrade Cloud
assistance.
£1,508.00

16. 16
- Has average throughput
Gb Ports, 1x WAN, etc.
- Uses 10 concurrent Ipsec
VPN, encryption
supported.
- Capable to offer up to
550 Mbps firewall
throughput and 94 Mbps.
Switch TP-SG1005D - Gigabitport. £14.99
a. VPN would be more secure method incorporate in remote access into the
system. Public networks in a group, exchanges data in more secure way-
using VPN. VPN can be create using different types of protocol to
establish virtual point-to-point connections to tunnel the traffic.
Component required to build VPPN
 VPN client.This system is used with credentials, this will connect the main
server. VPN client will be configured on both computer and router.
 VPN server. The link port for the VPN client will be the VPN server. It operate
precisely like a router. The VPN will give private access to users over the
network.
Task 5 Remote access

17. 17
 IAS Server. To proceed the task given, we will require ADIUS in order to build
VPN, this will authenticates people that connect to the network via the VPN.
 Firewall. Since the VPN will accept external connection (outside world).Users
has a direct access to the server. And for that reason, Firewall is required in
order to block users who are not supposed to be part in our network.
 Tunnelling Protocol.There are several examples of tunnelling protocol, such
as PPTP (Point-To-Point Tunnelling Protocol), L2TP (Layer 2 tunnelling
Protocol). PPTP has characteristics such as authentication, encryption etc.
Concerning L2TP, it does not offer authentication, encryptioncharacteristics.
On L2TP, it transmit packets within UDP datagram. (Rouse M. ,
www.searchnetworking.techtarget.com, 2017)
 IPsec. It is a protocol suite, which offer privacy and authenticate the data sent
through the network. IPsec have two sub protocols, that is, ESP and AH. AH
uses hash operation to cover up packets headers and other data packet.
IPsec has two modes of operation that are Transport Mode and Tunnel Mode.
Transport Mode encrypts data only, while both data and header are encrypted
in tunnel Mode (TM). (Geeksforgeeks, n.d)
 Google docs. This will not be a good way to share information over the
internet because the authority of the security can spread business data.
b. How Mobile devicecan influence the network security
If smart (mobile) devices have remote access to the organization network,
there would be an open port to hacker. If the system is less secure, the
more it will be attack and influence by hackers. If an inflected device
(phone) have remote access to the network, the device can transmit files
to the system, which can change the behaviour of the systems (failure).
c. security concerns relating to introducing Office 365
 Introducing office 360 will provide a service where document can
be access anywhere using the cloud. Concerning their security
factors. Also security can be strict meaning that not everyone will
have permission to access document. (Moran, 2015)

18. 18
 As far as computer systems can damaged. using office 360 will
serve as a backup system which will safeguard all your crucial
data. (Moran,2015)
d. Benefits of using VoIP
 It serves as multi function. VoIP system helps to conduct
videoconferencing, call forwarding, call waiting, paging etc. Help
users to get in touch with each other by discussing important deals,
affairs, meetings etc. (Collins, 2019)
 Efficient and secure. VoIP is efficient and secure. It allow data/
communication to run smoothly over the network that save
business cost. Concerning about organization security, VoIP uses
standardized encryption protocols which is difficult to provide on
telephone connections. (Collins, 2019)
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