CASE STUDY PROMPT: Plains Research Institute is a private organization of 22 phy

Question

CASE STUDY PROMPT:

Plains Research Institute is a private organization of 22 physical chemist and a business management staff of eight, including a computer support professional. The organization obtains research grants from corporations and government organizations to develop new or enhance existing chemical processes. For example, one group of chemists is researching the development of automotive engines to run on hydrogen. Another group of chemists is developing a better way to extract natural gas from coal-bed geologic formations and pump the natural gas to customers. Plains Research Institute has leased a building on a university campus for five years, but now the university has other plans for that building, and so Plains Research Institute is purchasing a new building. They want to network the building and have hired you through Network Design Consultants. The building is a single-story building. All of the employees use either Windows 7 Professional or Fedora Linux on their workstations. The organization also has four Red Hat Enterprise Linux servers and one Windows Server 2008 R2 server. The old network in the university building contained a combination of unmanaged hubs and unmanaged switches. Because the Plains Research Institute president and management staff are very concerned about security, they have decided this will be a wired Ethernet network without a wireless component.

CASE STUDY 5-4 Addressing Internet Security

In relation to Internet connectivity, both you and the chemist at Plains Research are concerned about security. What network device or devices can be used to address the concern about security?

Explanation / Answer

Tmain TCP/IP network setup files used by Linux to configure different network services of thesystem such as IP Address, Default Gateway, Name servers DNS, hostname and much more.

Any Linux Manager must be well aware where these services are configured and to use them.

On most Linux systems can access the TCP/IP connection details within 'X Windows' fromApplications > Others > Network Connections.

How To Set Up A Linux Network: .

Before we get into setting up Linux networking on a Desgin system well cover the basics of howto set up a network with both Windows and Linux systems and how to make it a "private"network.

Here the term "private" has to do with the IP addresses use on business network.

Then understand the value of having a proxy/NAT server or a firewall system which alsoperforms the proxy/NAT function on your network.

We'll briefly talk about/say what you need to look at on Windows PCs and present more in-depthinformation on which files are used on a Desgin system to set up networking.

The Network Setup Files section shows what files are involved in setting up Desgin system towork on a local network and how they need to be configured to enable the different functionsinvolved in networking including being able to connect to the Internet.

"Private" Networks .

Probably (but not definitely), every system on a network needs a (like nothing else in the world)identifier a (like nothing else in the world) address . So, every system that accesses the Internetwould need a (like nothing else in the world) IP address because TCP/IP is the rules of conduct ofthe Internet.

However, when the Internet exploded in the mid-90s it became clear that there simply were notenough addresses available in the TCP/IP address space for every computer in every office ofevery Internet-connected organization.

That doesn't even take into account those who wanted to access the Internet from home.

The solution was to create "private" address ranges to be used along with "addresstranslation".See the process .

Three blocks of IP addresses were set aside as private, meaning that all of the routers on theInternet would be configured to not route them.

The benefit private addresses If packets from systems with private addresses weren't routedbetween Internet-connected networks, then a whole bunch of networks could use the sameprivate addresses because they'd never "see" each others addresses.

In other words, these same addresses could be used by any number of computers around theworld because if they weren't routed, it would never be "discovered" that they weren't (like nothing else in the world).

So if they're not routed, how do get on the Internet if computer has a private address assigned toit That's where the second piece of address translation, comes in.

(usually/ in a common and regular way), in order for all the computers in a company to haveInternet access they would all have to be assigned routable "public" IP addresses that could passthrough the Internet.

Since there aren't enough addresses for this, companies instead assign all of the hundreds ofcomputers in their organization private addresses and they all share a single "public" address toaccess useful things/valuable supplies on the Internet.

This sharing is very skillful by configuring privately-talked to/looked at systems to use a specialserver, called a (related to being a substitute for someone or something) server, to access theInternet.

A (related to being a substitute for someone or something) server has two NICs (Network(connecting point/way of interacting with something) Cards) because it's connected to twodifferent networks.

One NIC is connected to the Internet and is assigned a single "public" routable IP address.

This NIC is referred to as the "external (connecting point/way of interacting with something)".

The other NIC is connected to the company's internal network.

It is assigned a private IP address so that it can communicate with all of the other privately-talked to/looked at computers in the company.

This NIC is referred to as the "internal (connecting point/way of interacting with something)".

The (related to being a substitute for someone or something) server acts as a "gateway" onto theInternet.

Because of the gateway behavior, a (related to being a substitute for someone or something)server should also have firewalling abilities to protect the internal network.

However, in addition to acting as a gateway, it acts as an address translator.

The private IP addresses assigned to the systems on your internal nework are chosen by fromone of the three private address ranges listed below.

Public IP addresses are only available from an ISP.

In most cases, such as with a dial-up, DSL, or cable modem, your ISP automatically assigns asingle public address to your modem using PPP, bootp, or DHCP.

This assigned address can change from time to time "energetic/changing" . It needs/demands nosetup on your part.

Business customers usually get multiple public addresses from their ISP.

These addresses do not change "static" . Static addresses are needed for Internet servers thatare referenced by DNS records such as Web servers, mail servers, etc.

that are contacted using a domain name.

When a computer on the internal network with a private address wants to request informationfrom a Web site, it actually sends the request to the internal (connecting point/way of interacting with something) of the (related to being a substitute for someone or something) server.

The (related to being a substitute for someone or something) server, with it's public routableaddress on the external NIC, is the one that actually sends the request to the Internet Webserver.

The Web server sends the response back to the substitute server's external NIC, and the (related to being a substitute for someone or something) server then forwards the response on to thecomputer on the internal network that made the first request.

The (related to being a substitute for someone or something) server keeps track of which internalcomputers make which requests.

The advantage: Hundreds of computers in a company can access the Internet and only take up asingle public Internet address that of the substitute server's external NIC . Another advantage issecurity.

If computer's address can't be routed over the Internet, it would be hard for someone to get atyour computer from the Internet.

The translating of a private address to a public address outbound request and back again inbound response is most commonly known as NAT (Network Address Translation .

In the Linux community it's also often referred to as "pretending" because the related to being a substitute for someone or something server hides the true identity of the internal computer thatmade the first Internet request.

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.