Network Infrastructure Upgrade for uSoft: A Layered Approach

Desklib provides past papers and solved assignments for students. This project details a LAN upgrade for uSoft.

ASSIGNMENT -3
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INTRODUCTION AND SUMMARY
Network scalability is a characteristic of any design that forecasts the growth of the network
over a successive period of time. These growth challenges the network designer or
administrator to incorporate certain elements into the design to remediate any instances of
network unavailability or reduced service levels experienced by users. At uSoft HQ, the office
local area network (LAN) requires a makeover to meet the increase in the customer base it
currently services. The company must enlarge her technical capacity and boost operations using
a new network model that will be proposed.
In each section of this proposed design, a different aspect of the new design will be discussed
and analyzed towards achieving the goal of engineering a new network that can keep the
business and user satisfied with uSoft offers. The first section will of the design document
describes the engineering of user requirements for the design in order to define the scope of
work and establish an understanding of the network. The preceding section builds on this by
proposing the logical network topology based on the size of the new network. In concluding this
work it is pertinent to provide detailed IP addressing information that can be used to configure
the new network.
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Table of Contents
INTRODUCTION AND SUMMARY...................................................................................................2
ORGANIZATIONAL PROFILE............................................................................................................4
ENGINEERING USER REQUIREMENT..............................................................................................4
BUSINESS REQUIREMENT...........................................................................................................4
TECHNICAL REQUIREMENTS.......................................................................................................5
LOGICAL DESIGN............................................................................................................................ 6
SECURITY DESIGN.......................................................................................................................6
WIRELESS DESIGN...................................................................................................................... 6
VLAN DESIGN............................................................................................................................. 7
IP ADDRESS ALLOCATION PLAN.....................................................................................................8
LOGICAL NETWORK TOPOLOGY...................................................................................................11
PHYSICAL NETWORK TOPOLOGY................................................................................................. 12
CONCLUSION............................................................................................................................... 13
REFERENCES.................................................................................................................................14
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ORGANIZATIONAL PROFILE
The company is a private biomedical software company with a HQ office and two branches
spread across the gold coast area. The company desires a redevelopment of its existing LAN
network in order to meet current business and technical goals that have challenged the existing
LAN network. The current network cannot support the current growth being experienced and a
new network is required to maintain satisfactory operations. As a software development
company. IT is the fuel behind all of its operations and business growth currently experienced.
ENGINEERING USER REQUIREMENT
A primary objective of the design focuses on two core aspect of the proposal as requested by
uSoft. The first is realizing the business requirements for proposing this design while the second
objective focuses on creating a network that meets a complex list of technical requirements.
Both requirements must be achieved before the design can be considered successful. For the
current design to meet the growth experienced by the company, communications.
BUSINESS REQUIREMENT
Proceeding with the analysis I will consider the business requirement first and how the new
design will achieve these objectives. Business process are driven by communications, uSoft
considers this a core business objective for the current design. Improving business
communication translates to client satisfaction and reduced project delivery duration. Wireless
networks provide mobility in the new age where traditional PC’s are not the only devices that
connect to the network. In the new design, I will incorporate wireless access points across the
office area in order to enable mobile computing devices to maintain connectivity are staff to
move around. Another business enhancer in the work environment that supports enhanced
communication is a voice over IP services. In the redeveloped design VoIP integration will be
considered and planned because if the quality of service requirements and bandwidth
reservation that must be configured for VoIP. Concluding the business requirements is the
object of ensuring the company’s digital assets are safe from malicious attacks. This is a security
goal that will be implemented using the right firewall device and applicable policies.
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TECHNICAL REQUIREMENTS
The technical objectives defined by the company involves a set of goals that must guide the
infrastructure build process. At the apex of this requirement is the desire to have a network
that is scalable and will eliminate the current exercise in the nearest future. A scalable network
is one that can adapt to any anticipated future growth without affecting the core components
of the network. To implement scalability a layered design approach will be adopted for the new
model. A layered network is made up of blocks of devices that function to achieve different
desired goals.
Remote access eliminates the network boundaries that restrict work to a single location by
enabling users to connect their devices from any public infrastructure and work remotely. To
connect securely a virtual private network VPN) must be configured and in this case a remote
access VPN. Firewall and routers can be used to terminate VPN access before connecting to the
local LAN. Network performance is a requirement aimed at providing a satisfactory experience
for users accessing different services on the network. To measure user satisfaction, service level
agreements must be defined and maintained across the network. A simple test of performance
can be viewed as slow links or latency of connectivity. To provide the requisite performance,
the network will use gigabit links for uplinks and FastEthernet links for downlink connectivity.
A network must be able to provide security for users connected to it and data stored on the
network. Security will be implemented by adding a firewall to filter traffic, provide anti-malware
services and protect the network form any form of attack. To measure the efficiency of the new
design I will consider the network uptime. If users’ loose connectivity to a network resource or
it becomes unavailable the uptime of the network decreases. A simple approach towards
ensuring availability that will be visible in the redeveloped design involves a redundant pair of
devices and redundant links.
Without segmenting the networking, achieving the highlighted objectives will be very difficult.
A VLAN is a separate broadcast domain that is isolated from other subnets but the creation
takes place at layer2. The separation of work groups, resources and services simplify network
administration and management. A VLAN segmented network reduces the size of broadcast
traffic which can be challenging to manage in large networks. The deployment of VLANs in the
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current network will create a VLAN for each department before applying inter-VLAN routing to
permit communication between the subnets.
LOGICAL DESIGN
The proposed solution is a layered network model consisting of an access layer and a
core/distribution layer. In addition, a WAN edge portion of the network has a router and a
firewall that segments the network into three zones. Each layer of the network interoperates to
provide unique functions that enhance connectivity.
SECURITY DESIGN
To secure the network, a firewall will be placed between the internal segments, the DMZ and
the WAN edge router. A DMZ zone is an area of the network that harbours the servers and
protects the services in the internal networks from any external access. By implementing a DMZ
the desired policies and control can easily be implemented and managed.
WIRELESS DESIGN
The design of a wireless network is centred on providing connectivity, mobility and security for
network users. A wireless LAN (WLAN) is a WI-FI network for a LAN user group. The deployment
uses several standards and protocols that serve to guide the usage of the frequency bands.
WLAN extends the boundaries of the physical cable connection by providing mobility for users.
The components that make up a WLAN are wireless access points, wireless controllers and
wireless network interface cards (NIC). An access point is a wireless transceiver that broadcast
the signal and processes user traffic. In large deployments, the use of wireless controllers
provides a simplified approach to AP management (Barker, 2015).
The wireless network of uSoft will be built using a wireless LAN controller and wireless AP. The
AP’s will be connected to the access layer switches and provide connectivity within the work
areas for adequate coverage of the work area, 9 AP’s will be used for the entire floor plan. A
sample design of the connectivity will be highlighted in the network topology.
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Figure 1: Wireless Network architecture
VLAN DESIGN
The virtual LAN (VLAN) design for uSoft will adopt a simpler approach by segmenting the
network into the different departments. This approach enhances the security of the network by
preventing users in one VLAN from accessing resources in another VLAN.
For the new network, I will create individual VLANs for the six departments on the LAN. The IP
address allocation plan will also be designed to fit into the VLAN segments. This will simply
connectivity, security administration and manageability of the entire network.
Figure 2: VLAN design
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IP ADDRESS ALLOCATION PLAN
IP is a network layer transport protocol for IP datagrams. IP encapsulates upper layer protocols
for transmission to a destination host. It also provides a mechanism for uniquely identifying
each host on the network based on their location on the network and offers the ability to
isolate host. IP is represented as a numerical decimal value which is 32bit in size and consist of
four groups of 8 bits separated by a dot. The value can also be written in binary but for ease of
usage it is often written in decimal form. An IP address has two sections, a network and a host
portion. The host portion identifies a NIC on a network device. The network portion indicates
the location of a device on the network. Two devices on separate networks cannot
communicate directly.
In order to differentiate the host and network portion of the address an additional value is
attached to the IP address called the subnet mask. A subnet mask is also a decimal value with
unique values between 0 and 255.
To design an IP address allocation plan for uSoft which has 6 departments; Software
Development, Solution Design, Customer Support, Sales, Finance and Human Resource. The
class B address space 172.16.1XY.0 with subnet mask 255.255.252.0 (/22) was allocated for the
design. Where XY represents 23. The address is 172.16.123.0/22.
The address prefix allocates to uSoft is 172.16.123.0/22. This address will be subnetted using
the variable length scheme.
The break down for the host requirements is as follows:
1. Software development: 207
2. Solution Design: 186
3. Customer Support:: 125
4. Sales: 105
5. Finance: 65
6. Human Resources: 45
The network 172.16.123./24 is allocated to Software development.
This leaves 3 networks
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The next subnet requires 8 bits s also, therefore 172.16.125.0/24 is allocated to Solutions
Design.
Solving for the next network 125 hosts requires seven bits
The next address is 172.16.125.0/24, the difference between the number of host bits and
available bits give 1.
For 1 bit we have 2 networks these are 172.16.125.0/25 and also 172.16.125.128/25.
We allocate 172.16.125.0/25 to Customer Support.
Sales network also requires seven bits, therefore, we can allocate 172.16.125.128/25 to
Department Sales subnet.
Solving for Finance subnet using the network 172.16.126.0/24, this subnet requires seven bits.
This leaves 1 bit for the network which gives us two networks. 172.16.126.0/25 and also
172.16.126.128/25
The first subnet address 172.16.126.0/25 is allocated to Finance department.
The last subnet is Human Resources with 45 hosts.
This network requires six bits
The available network address is 172.16.126.128/25, the number of host bit required for this
department is 6 host bits, this leaves 1 bit for the network resulting in 2 networks
172.16.126.128/26 and also 172.16.126.192/26.
The first network 172.16.126.128/26 is allocated to Human Resource.
(Lammle, 2011)
DEPARTMENT NETWORK
ADDRESS
NUMBE
R OF
hosts
HOST ADDRESSABLE
RANGE
GATEWAY
ADDRESS
BROADCAST
ADDRESS
SOFTWARE
DEVELOPEMENT
172.16.123.0/24 207 172.16.123.1 –
172.16.123.254
172.16.123.1 172.16.123.254
HUMAN
RSOURCES
172.16.126.128/26 45 172.16.126.129 –
172.16.126.190
172.16.126.129 172.16.126.191
SOLUTION
DESIGN
172.16.124.0/25 186 172.16.124.1 -
172.16.124.254
172.16.124.1 172.16.124.254
SALES 172.16.125.128/25 105 172.16.125.129 – 172.16.125.129 172.16.125.254
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172.16.125.254
CUSTOMER
SUPPORT
172.16.125.0/25 125 172.16.125.1 –
172.16.125.126
172.16.125.1 172.16.125.126
FINANCE 172.16.126.0/25 65 172.16.126.1 –
172.16.126.126
172.16.126.1 172.16.126.127
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LOGICAL NETWORK TOPOLOGY
The logical network for concluding the proposed design is shown below and also depicts a
topology with all of the required components.
Figure 3: Logical Design Diagram
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PHYSICAL NETWORK TOPOLOGY
A physical topology is similar to the logical topology and depicts the physical interconnection
between end host, switches, firewalls and routers.
Figure 4: Physical Design Diagram
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