A little bit of background follows. Crystal Limited is an award winning design consultancy with many years experience in creating hotel, leisure and retail environments for design led clients worldwide. The company is currently experiencing growth and is opening new offices in major UK locations. Funding has been released for improvements to its network services. A key requirement is the network design should provide a high level of reliability and scalability to meet the needs of future growth.
Ethernet hubs are typically used to connect workstations to the network, and the Nottingham, Liverpool, Leeds and Derby offices are equipped with a modern cabling infrastructure which is adequate for supporting a modern campus network. However the Manchester headquarters uses a legacy category 3 cabling infrastructure which was pre-installed in the building. Employees at the Manchester site report frequent problems with performance and network failures. Each site has a single flat IP address space. Currently, Crystal Limited has a contract with a single ISP.
The current link is a 2 Mbps circuit provisioned to the Manchester headquarters. The ISP has assigned a subnet of 201. 19. 0. 0/29 for the internet connection. The Crystal router should be configured with the highest usable address within the subnet. The ISP router has been configured with the lowest usable address. Crystal uses the Internet connection for web browsing and corporate e-mail. The corporate e-mail server should be situated inside a separate subnet attached to the Crystal perimeter router. It should be reachable from the Internet at a fixed address.
2. Proposed Approach Crystal Limited requires a design for a major network upgrade. The solution should support current levels of staff and a projected increase of 25% over the next year. High availability is a key requirement, so it is expected that redundancy will be factored into the design of the solution. The design should include both LAN and WAN infrastructures, a network addressing scheme which covers the entire solution and routing protocols. There are some specific additional requirements which must be incorporated into the proposal.
Crystal Limited are requesting you provide a Network Design Document for a solution which meets the requirements below. A good response like the one below not just say what or how, but it also states why. In other words it attempts to: fully explain and justify important design and implementation decisions; look at alternatives; and even explain why something does not work, and in a commercial context often, it is asked, why us? The element of explaining “why” implicitly provides one with a vehicle to demonstrate one’s expertise and knowledge.
The response below will also set out important assumptions that have been made, identification of important limitations with the following solutions (e. g. requirements not met), and even unique features and additional advantages should be examined which are offered by these proposed solutions. The following is a narrative that provides easy traceability to customer requirements. • The ability to: conceal the details of the customers’ addressing scheme from the internet, allow web browsing; allow for the corporate e-mail server to be reachable on the Internet.
This will be achieved by making sure an effective plan is put in place so that customers’ information can be protected. The addressing scheme can be placed on a server on the Internet so that any information is password-protected. In this way, many people will be able to use the system without fear of retribution or having to worry that someone else will access their information. Many times what is necessary in order to protect a network is the ability to make sure that it is secure in every sense of the word. Firewalls should be used in order to ensure that there are no malicious malwares or annoying pop-ups on the server.
This would allow for a decent amount of web browsing in a safe manner for all users who would be employed at Crystal. Safe web browsing is important in any kind of company structure. In order to proffer web browsing that is safe for the entire company, it is important to lay groundwork or rules as to how company Internet usage can be utilized. First of all, employees should be made aware of the fact that certain web sites are banned from being viewed, such as any web site which has pornographic or otherwise inappropriate content.
Secondly, employees should be made aware of the dangers of opening attachments from any outside third parties. Many a computer virus or worm has been spread through one person’s opening of attachments. That is why it is important to stress to employees the necessity of not opening attachments. The corporate e-mail server will also be able to be available on the Internet through creating a LAN network that would be for the various corporate offices individually. Then, a WAN network would be created in order to unite all the LAN’s that would be created for the company’s individual offices.
The corporate e-mail would be on a main server at some remote location. This would be so that if there were ever any type of problem, the server could be easily accessed. The difference between LAN’s and WAN’s will be discussed later on in the paper. • A resilient wide area infrastructure which will allow each site to connect to the Manchester headquarters should there be a failure in the leased line network shown above. In the event of a link failure the network should be able to begin using an alternate link within 10 seconds.
There should definitely be a link that the server could revert to should the main site being maintained should fail. • A design for a cabling infrastructure which will solve the current problems within the Manchester office. A cabling infrastructure would have to be designed which would not be very invasive and addressed all the problems corollary to this type of set-up. • The network addressing scheme should be based upon a class B network address which will not clash with existing addresses already used by organizations connected to the Internet.
The addressing scheme should be adequate to provide addressing for the projected staff numbers mentioned above – however the customer would like the remainder of the address space to be conserved for future use. Please note that the addressing scheme must cover all local area segments and wide area links. The addressing scheme should be varied enough not to clash with other networks, but should be distinct enough so that the company’s addressing scheme is separate from the others. • Traffic from each department should be logically separated from other departments.
Your LAN solution should allow the movement of users from one physical location to another within their building. Such a move should not require IP settings to be reconfigured on the users’ workstation. IP settings should be discretely separated and used as needed. Web traffic should be encouraged but each office’s traffic should be separated. The LAN should be set up in such a way so that users are not confined to one place in the computer lab, but can actually move around without fear that their information will be compromised. • Network diagrams which show the layer 3 topology of the WAN and LANs, (including active networking devices).