Vlan And Ip Address Specification Computer Science Essay

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The following documentation presents a Network design for newly started OPTICHROME Ltd Company which provides special effects for film and television industries. The Company is divided into three managerial divisions each having different number of employees working and also has different data transfer rates requirements. The first division is rendering and production division consists of 10 employees having 2 computers per employee. Out of which one computer per employee is dedicated for rigorous task of rendering animated frames amongst other computers in that division. At night all the computers in rendering divisions transfer the animated frames while doing so the data rate between two computers must be about 300 Mbps.

The 2nd division is Animation and Modeling division having 20 employees with one computer per employee. This division sometimes requires that two or three computers may need to be linked for project so peak data rate required should be around 50 Mbps. Third division is Marketing, sales and administration which employees 10 people having one computer per employee and data rates required would be up to 10 Mbps.

Also there is CEO and two divisional managers each having one computer with data requirement of 10 Mbps. The company has plans to expand the employees by up to 50%. To serve the above requirements of the optichrome Ltd, has gained address range around netID By using appropriate IP address subnetting and vLAN's we can reach the company requirements. Also by using different categories of cables like CAT5, CAT5E, CAT6 we can meet the data rate requirements of each divisions.

Data Network design

For the data network design we have to consider all the network topologies which we are going to use also the network equipment's like switches, routers and the cabling requirements for the network design.

Cabling Requirements

First of all we will consider the cables which we are going to use for the network design. The building space that company is about rent has a CAT3 based twisted pair cable network which is currently used for telephony and 10 Mbps networking. But there are some disadvantages in using CAT3 cable for the networking in the Optichrome Ltd so to avoid this we will use better alternatives for CAT3 cable.

The Limitations of CAT3 cables are:

CAT3 cable provides the transmission speed up to 10 Mbps only whereas the data transfer rate required by the company are much higher than 10 Mbps. Therefore we have to avoid the use of CAT3 cable.

We can achieve better efficiency and higher transmission speed by using following cables:

CAT 5 cable

CAT 5 is unshielded twisted pair cable. The main advantage is that Category 5 cable is typically used for networks running at 10 Mbps or 100 Mbps. The maximum length (maximum certifiable length) for CAT 5 patch or crossover cables is 100 meters. This cable assists the data transfer rate requirements for administration sales and marketing and animation and modeling division which is 10Mbps and 50 Mbps respectively.

CAT 5E/CAT6 cable

CAT 5E is an enhanced version of CAT 5 cable. This cable is designed for transmission speeds up to 1 gigabit per second (1 Gbps) which is more than sufficient for the company's requirements of the data transfer rates. This cable has 100 meters range and highest data rate in order to fulfill the requirement of each division of the company. The rendering and production division has got highest data transfer rate (300 Mbps) requirement amongst all the divisions which is fulfilled using CAT5E/CAT6 cable.

Networking Technologies & equipment

The core networking equipment's which we are going to use for the Network design are layer 3 switches.

The network topological diagram for the network design should be as follows:

Figure 1

The above topological diagram shows the inter-connection between layer 3 switches and vLAN's linked to them.

There are four layer 3 switches used for the network design. Layer 3 switches are connected through their trunk ports with each other in such a way that data can be directly transmitted amongst them and their respective vLAN's.

The connection link shown in black colour from switch 1 to vLAN 1 is wired by using Cat 5e cable. And the links shown in red colour are wired to their respective vLAN's from their respective switches using Cat 5 Cables.

Now vLAN configurations for each division will be as follows:

For vLAN 1, there will be 20 computers connected to a switch 1 which will be in cluster to facilitate the transfer of frames amongst the computers. The switch used here will comprise of 48 ports because maximum requirement of the division will be of 30 computers considering future expansion.

In vLAN2, there would be 20 computers connected to switch 2 and these computers can be operated independently. Also some computers can be linked together for project if required. The switch 2 is comprised of 48 ports so that maximum of 30 computers can be configured to the vLAN.

In vLAN3, there would be 10 computers connected to switch 3. The switch consists of 24 ports as the requirement for this division is of 15 computers considering the expansion of workforce in future.

And finally vLAN 4 and vLAN 5 will be residing under switch 5 assigned to divisional managers and CEO respectively. This switch is also comprised of 24 ports which is adequate for them. Both the vLAN's are configured on different ports of layer 3 switch.

2.3 Physical Layout Diagram

Now depending upon above network topological design physical layout of the floor can be shown as follows:

Figure 2

Now as per the above floor design the layer 3 switches can be placed inside the SERVICE BLOCK region where the power cabinets and service ducts are positioned to provide the power supply to all the switches.

Starting from the service block the cat 5 cables can be wired over the CEO's office, Admin division, the sales and marketing department, animation & modelling division and 2 divisional manager's cabin.

Likewise the Cat 5e cable can be wired towards the Rendering and production division to facilitate the data transfer.

The network design will consist of individual subnets allocated to different division of the company. The design will be composed of IP subnets and vLAN to achieve the requirements of the company. Each division will be divided into separate vLAN. The entire network will be divided in the following manner:

Rendering and Production division will come under vLAN 1 and it will include of 20 computers as per the company requirement.

Animation and Modelling division would be allocated to vLAN 2 and it will also include 20 computers.

Administration, Sales and Marketing division would be allocated vLAN3 which will comprise of 10 computers.

Divisional managers will come under vLAN 4 having 2 computers.

And for CEO there would be an independent vLAN assigned which is vLANdilouge 5.

VLAN and IP address specification

The OPTICHROME LTD have acquired the IP address range around the net ID thus we have 256 distinct IP addresses for the computers which will be used in three different divisions. But to do so, we have to divide these 256 IP addresses amongst the four different subnets of the given IP address range and depending upon those subnets we can create three distinct vLANs for three divisions of the company and in addition to this one separate vLAN for the CEO and two divisional managers. We can use different subnet mask to design different subnets according to the requirements of each division, which will take into account the future expansion of the workforce of individual division of the company. Also each subnet has its own Network ID and broadcast ID which will differentiate it from other subnets. Each subnet designed in the network corresponds to separate VLAN which consist of all the IP addresses assigned to particular computers in that particular subnet.

The IP address allocation amongst the three Divisions of company can be shown as follows:

Rendering & Production Division

To start with the first division of the company, there are 10 employees and having two computers each so overall 20 IP address are required at first glance. Thus to make the first subnet we will use 27 as subnet mask which will give us 32 IP addresses for the host side to take care of any expansion of the workforce in the division. The address allocation is shown as follows:

Network address for 1st subnet is

IP addresses from to are allocated to 20 computers present inside the division.

Also this division can use the addresses up to, the provision of extra IP addresses are promising so that if future expansion is done in this division then sufficient IP addresses should available to them.

The broadcast address for this subnet will be

All the above computers will come under single VLAN which will be VLAN1, also this division has special requirement of rendering animated frames between the computers dedicated for this purpose, and this can be facilitated by using one VLAN. So we can summaries the address allocation as follows:

Network ID -

For Current use - to

For Future use - to

Broadcast ID -

Animation & Modeling Division

This division also requires 20 IP addresses for 20 computers so to continue with the above subnetting we will require 32 IP addresses for the host side of this division too. Here also we are using the 27 as subnet mask because we have to take care of the expansion of the workforce by the company in future. The IP addresses will be allocated as follows:

The Network address for this 2nd subnet will be

IP addresses from to are allocated for the 20 PC's so that basic need of this division is satisfied.

Also IP addresses from to are available for this division if there is any need of future expansion of the workforce.

The broadcast address for this subnet will be

The IP addresses from to will be assigned to vLAN2 which will facilitate the working of Animation and Modeling division. The separate vLAN provided for this division will take care of the condition where two or more computers are required to be linked for the project. So we can summarize the address allocation for this division as follows:

Network address -

For current use - to

Future use - to

Broadcast address -

Administration, sales & Marketing Division

This is the third division of the company which is having 10 employees with one computer per employee. Therefore we will design the 3rd subnet for this division which will consist of 32 IP addresses. For the design purpose we will use 27 as subnet mask which will give us 32 IP addresses to take care of total workforce in this division.

The Network address for this subnet will be

IP addresses from to are allocated for the 10 computers so as to provide with basic needs.

Also IP addresses from to are available for this division for the purpose of future expansion of the workforce which may be done by company in the future.

The broadcast address for this subnet will be

So the total IP addresses from to will come under VLAN 3 to serve the working of Administration, sales and marketing division. All IP addresses in this subnet are assigned to VLAN 3. We can summarize the address allocation for this as follows:

Network address -

For current use - to

For future purpose- to

Broadcast address -

CEO and Divisional Managers

The optichrome Ltd has one CEO and two divisional managers who are managing the company. The CEO and both the divisional managers have one computer assigned. The requirement of the IP addresses for them is small as compared to the other divisions therefore we can choose different Subnet masks to design the 4th subnet as follows:

Using 29 as Subnet Mask: If we use 29 as subnet mask then we will be available with 8 IP addresses. Out of which 3 will be used for CEO and two divisional managers and one for network ID and broadcast ID each. We will remain with 3 more IP addresses for the future use but there is risk in considering only 3 IP addresses for future use.

Using 28 as subnet mask: By using 28 as subnet mask total 16 IP addresses are available on the host side that are more than sufficient for CEO and divisional managers including the future expansion. This will also cover the Network ID and broadcast ID. Therefore we will prefer 28 as subnet mask. The IP address allocation for this subnet will be as follows:

The network address for this subnet will be

The IP addresses from to are allocated for three computers which represents CEO and two divisional managers.

Also the provision of IP addresses from to can be used by the company while considering the future expansion of these posts.

The broadcast address of this subnet will be

All the above IP addresses of above from to will form one subnet. The two divisional managers will be assigned to vLAN4 and vLAN5 will be comprised of CEO.

We can show the above specification for IP address allocation and VLAN in the tabular format as follows:

Serial No.


IP Address range

Subnet mask used



Rendering and Production





Animation and Modeling





Administration, sales and Marketing





Two Divisional Manager and CEO



4 & 5

The total numbers of IP addresses available to us are 256 that is from to but we are only using 112 IP addresses in our network design with the consideration of future expansion of each division in the company that are from to using four subnets. Means still the company has got 144 IP addresses remaining which they can use in future if required.

Critical Analysis

The critical analysis of the above designed network can be done as follows:

Strengths of the Network design are as follows:

First of all the network is designed using the layer 3 switches which itself act as routers so they can be extensively used for data transfer. Switches are connected to each other through their trunk ports and therefore in future information can be transferred between the vLAN's through inter vLAN routing if necessary.

The network is designed using layer 3 switches hence routers are not required which makes the design cost-effective & also suffice the higher data transmission speed between the vLAN's and switches.

Additional Strength of the design is the cables used for the data transmission. The Cat 5 and Cat 5e cables facilitates all the data rate requirements of the company including their lengths (up to 100 meters) over which they are wired inside the building.

In the design IP addresses are divided into different subnets as per the requirements of each division and we have used different subnet mask so as to have optimum use of IP addresses while considering the future expansion in each division. Perhaps this, we are left with 144 IP addresses out of 256 that can be used in the future.

The design has conserved the hierarchy inside company by creating different vLAN's for managers and CEO which also provides logical separation from their respective departments.

Limitations of the Design are as follows:

Though we have use layer 3 switches for design, it has some limitation that it leads to the formation of data loop (Broadcast storms) which is hazardous and can lead to congestion in the network. Therefore in order to avoid this we can make use of Spanning tree protocol and Bridge protocol data units which logically separate the links responsible for the data loops inside the network.

The design provides different subnet for managers and CEO which maintains the hierarchy but for that managers have to communicate with their respective divisions using different vLAN's which can cause delay. Instead of this generous design could have been served the requirement in which managers will be placed in their respective department's vLAN's.


In order to implement all the necessary and sufficient requirements and of the OPTICHROME Ltd we have put up the above Network design. The flexible network technologies and equipment's are used to facilitate the company requirements.

We have used the different vLAN's and subnets to serve the purpose of distinct divisions of the company. The Network design also considers the future expansion of the workforce which is reflected in designing and assigning the IP addresses to various subnets. There are very few loopholes in the network design but they can be avoided using some advance protocols. Therefore to conclude the above network design is appropriate for the OPTICHROME Ltd for their implementation.