THE FOLLOWING COMPTIA IT FUNDAMENTALS EXAM OBJECTIVES ARE COVERED IN THIS CHAPTER:

• 1.4 Identify the following alternative technologies and their purpose
  • Virtualization
    • Physical machine vs. virtual machine
  • Cloud computing
    • Streaming media (audio/video)
  • Web applications
• 4.3 Compare and contrast different methods of sharing and storage
  • HTTP vs. HTTPS
    • Browser-based file downloads
  • FTP vs. FTPS vs. SFTP (Secure File Transfer Protocol)
  • Local vs. hosted storage
    • Cloud-based services
      • Cloud-based collaborative applications
      • Cloud-based storage
    • File and print sharing
      • Workgroup
      • Homegroup
    • Network drives
    • Network attached storage
    • Direct attached storage
    • External hard drives
    • Peer-to-peer
      • Local adhoc network
        • Bluetooth sharing
      • Direct link (PC-to-PC)
      • Online peer-to-peer network
    • Network vs. local printing
      • USB
      • Wireless / wired network

In Chapter 5, “Networking Technologies and Wireless Routers,” you learned the basics of computer connectivity and setting up your own network. As part of setting up your own network, knowledge of TCP/IP is important to understand how computers talk to each other in a networked environment. In this chapter, you'll take the next step forward and learn how you actually share resources such as files, printers, and applications over the network.

This chapter starts off with a section on local network sharing. First, I will cover some core network concepts that will help your general understanding of networking. After that, I will spend time on storage options, and then I'll finish up with a discussion on how to share files and printers with other users.

Then this chapter takes a wider view of network sharing, by looking at web-based sharing and access. Many of the concepts are similar to those in local network sharing, but there are some exceptions. Most notable for the discussion here are cloud computing and accessing resources via the Internet. After this chapter, not only will you know how to connect computers together on a network, but you will be able to share resources between them as well.

Local Network Sharing

People use networks to get access to resources they normally wouldn't have. One big example is that we use networks to get on the Internet, which gives us access to an endless stream of information on news events, shopping, sports, hobbies, or whatever else we could be interested in. Closer to your home or office, perhaps you want to purchase only one printer and share it among your co-workers or family. That definitely saves money, and the only way everyone can use it is with a network.

In this section you are going to learn details of local network sharing, which is also the foundation for more distributed-resource sharing that is covered later in this chapter. First, you will learn about different types of networks. This will give you the background and vocabulary needed to understand the concepts throughout the chapter. After that, you will learn about local storage options. After all, the files everyone needs have to be stored somewhere, right? This section will end with a discussion on sharing files and printers on your network, so everyone has access to the resources they need.

Network Types

You might have read the title to this section and thought, “Wait a minute, I learned about wired and wireless networks in the last chapter. Aren't those network types?” The answer is yes, they are definitions of physical network types, but there are other ways you can categorize networks too, such as by the proximity of computers to each other or based on the roles computers on them play.

LANs, WANs, PANs, and MANs

Local area networks (LANs) were introduced to connect computers in a single office or building. Wide area networks (WANs) expanded the LANs to include networks outside the local environment and also to distribute resources across long distances. Generally, it's safe to think of a WAN as multiple, disbursed LANs connected together. Today, LANs exist in many homes (wireless networks) and nearly all businesses. WANs are becoming more common as businesses become more mobile and as more of them span greater distances. WANs were historically used only by larger corporations, but many smaller companies with remote locations now use them as well.

Having two types of network categories just didn't feel like enough, so the industry introduced two more terms. The personal area network (PAN) is a very small-scale network designed around one person. The term generally refers to networks using Bluetooth technology. On a larger scale is the metropolitan area network (MAN), which is bigger than a LAN but not quite as big as a WAN.

LANs

By the 1980s, offices were beginning to buy PCs in large numbers. Portables were also introduced, allowing computing to become mobile. Neither PCs nor portables, however, were efficient in sharing information. As timeliness and security became more important, floppy disks were just not cutting it. Offices needed to find a way to implement a better means to share and access resources. This led to the introduction of the first type of PC local area network: ShareNet by Novell, which had both hardware and software components. LANs are simply the linking of computers to share resources within a closed environment. The first simple LANs were constructed a lot like the LAN in Figure 6.1.

FIGURE 6.1 A simple LAN

After the introduction of ShareNet, more LANs sprouted. The earliest LANs could not cover large distances. Most of them could only stretch across a single floor of the office and could support no more than 30 users. Further, they were still very rudimentary and only a few software programs supported them. The first software programs that ran on a LAN were not capable of being used by more than one user at a time (this constraint was known as file locking). Nowadays, multiple users can access a program or file at one time. Most of the time, the only limitations will be restrictions at the record level if two users are trying to modify a database record at the same time.

WANs

By the late 1980s, networks were expanding to cover large geographical areas and were supporting thousands of users. Wide area networks (WANs), first implemented with mainframes at massive government expense, started attracting PC users as networks went to this new level. Employees of businesses with offices across the country communicated as if they were only desks apart. Soon the whole world saw a change in the way of doing business, across not only a few miles but across countries. Whereas LANs are limited to single buildings, WANs can span buildings, states, countries, and even continental boundaries. Figure 6.2 gives an example of a simple WAN.

FIGURE 6.2 A simple WAN

Networks of today and tomorrow are no longer limited by the inability of LANs to cover distance and handle mobility. WANs play an important role in the future development of corporate networks worldwide.

PANs

In 1998, a consortium of companies formed the Bluetooth Special Interest Group (SIG) and formally adopted the name Bluetooth for its technology. The technical specification IEEE 802.15.1 describes a wireless personal area network (WPAN) based on Bluetooth version 1.1.

The first Bluetooth device on the market was an Ericsson headset and cell phone adapter, which arrived on the scene in 2000. While mobile phones and accessories are still the most common type of Bluetooth device, you will find many more including wireless keyboards, mice, and printers.

One of the unusual features of a Bluetooth WPAN is its temporary nature. With other popular networking standards, you need a central communication point, such as a hub, switch, or router. Bluetooth networks are formed on an ad hoc basis, meaning that whenever two Bluetooth devices get close enough to each other, they can communicate directly with each other. This dynamically created network is called a piconet. A Bluetooth-enabled device can communicate with up to seven other devices in one piconet. Two or more piconets can be linked together in a scatternet. In a scatternet, one or more devices would serve as a bridge between the piconets.

MANs

For those networks that are larger than a LAN but confined to a relatively small geographical area, there is the term metropolitan area network (MAN). A MAN is generally defined as a network that spans a city or a large campus. For example, if a city decides to install wireless hotspots in various places, that network could be considered a MAN.

One of the questions a lot of people ask is, “Is there really a difference between a MAN and a WAN?” There is definitely some gray area here; in many cases they are virtually identical. Perhaps the biggest difference is who has responsibility for managing the connectivity. In a MAN, a central IT organization such as the campus or city IT staff is responsible. In a WAN, it's implied that you will be using publicly available communication lines and there will be a phone company or other service provider involved.

Peer-to-Peer and Client-Server Networks

In a peer-to-peer network, computers act as both service providers (servers) and service requestors (clients). An example of a peer-to-peer resource model is shown in Figure 6.3.

FIGURE 6.3 The peer-to-peer resource model

Peer-to-peer networks are great for small, simple, inexpensive networks. This model can be set up almost immediately, with little extra hardware required. Many versions of Windows (Windows 7, Vista, XP, 2000), Linux, and Mac OS are popular operating system environments that support a peer-to-peer resource model. Peer-to-peer networks are also referred to as workgroups.

Generally speaking, there is no centralized administration or control in the peer-to-peer resource model. Every station has unique control over the resources the computer owns, and each station must be administered separately. However, this very lack of centralized control can make it difficult to administer the network; for the same reason, the network isn't very secure. Moreover, because each computer is acting as both a workstation and server, it may not be easy to locate resources. The person who is in charge of a file may have moved it without anyone's knowledge. Also, the users who work under this arrangement need more training because they are not only users but also administrators.

Peer-to-peer resource models are generally considered the right choice for small companies that don't expect future growth. Small companies that expect growth, on the other hand, should not choose this type of model.

The other option is to have machines that are dedicated servers on your network. The client-server (also known as server-based) model is better than the peer-to-peer model for large networks (say, more than 10 computers) that need a more secure environment and centralized control. Server-based networks use one or more dedicated, centralized servers. All administrative functions and resource sharing are performed from this point. This makes it easier to share resources, perform backups, and support an almost unlimited number of users. This model also offers better security. However, the server needs more hardware than a typical workstation/server computer in a peer-to-peer resource model needs. In addition, it requires specialized software (a network operating system) to manage the server's role in the environment. Server-based networks can easily cost more than peer-to-peer resource models. However, for large networks, it's the only choice. An example of a client-server resource model is shown in Figure 6.4.

FIGURE 6.4 The client-server resource model

Server-based networks are also known as domains. The key characteristic of a domain is that security is centrally administered. When you log into the network, the login request is passed to the server responsible for security, sometimes known as a domain controller. (Microsoft uses the term domain controller, whereas other vendors of server products do not.) This is different from the peer-to-peer model, where each individual workstation validates users. In a peer-to-peer model, if the user jsmith wants to be able to log into different workstations, she needs to have a user account set up on each machine. This can quickly become an administrative nightmare! In a domain, all user accounts are stored on the server. User jsmith needs only one account and can log onto any of the workstations in the domain.

Client-server resource models are the desired models for companies that are continually growing, need to support a large environment, or need centralized security. Server-based networks offer the flexibility to add more resources and clients almost indefinitely into the future. Hardware costs may be higher, but with the centralized administration, managing resources becomes less time consuming. Also, only a few administrators need to be trained, and users are responsible for only their own work environment.

Storage Options

From Chapter 1, “Core Hardware Components,” you know that files are stored on hard drives. Regardless of whether the files you are accessing are on a local computer or across a network, they are stored on a hard drive somewhere. The question is just where and how you get to them.

Direct Attached Storage

The first option is direct attached storage (DAS), which is a fancy term for a very simple idea. It simply refers to any hard drive attached to a local computer. The hard drive that comes in your computer is a prime example of DAS, as is any external hard drive you might add.

DAS has an advantage in that it's the easiest of the storage systems to install and manage. If you can plug in a hard drive, either internally or externally, you can install and manage it. You can also make these hard drives accessible to others on the network via file sharing, which I will cover in a few sections. One downside to DAS is that if for any reason your computer is not accessible, such as if it's powered down or you are traveling for work, then other people can't access the files on the drive. A second is that different operating systems don't always play nicely with each other. If you are sharing your external hard drive on a Windows computer, someone with a Mac or Linux client might not be able to access it. This isn't always the case, but it can be an issue.

Network Attached Storage

Chapter 2, “Peripherals and Connectors,” introduced network attached storage (NAS) devices. If you'll recall, they are self-contained, external storage devices that typically contain two or more hard drives. In addition, NAS devices also have their own operating system and file-sharing mechanisms.

NAS solutions tend to be more expensive than DAS ones, and they can be a little harder to set up and manage. For example, they are connected to the network instead of your computer, and they come with their own software package for management. But the upside far outweighs the downside. First, since it's connected to the network, the NAS is available regardless of whether an individual computer is online or not. Second, you don't run into any file system compatibility issues between clients with different operating systems. Third, most NAS devices also come with extra utilities, such as built-in RAID or backup programs. If you're looking for something quick and cheap, DAS might do the trick. If you want something a little more permanent, stable, and flexible, then NAS is a better option.

Network Drives

A network drive is simply a hard drive on another computer that you are accessing. In most cases it's located on a server. From your computer's perspective, it doesn't matter if that drive is internal or external to the server, a NAS device, or anything else. Your computer just needs to know the location of that drive.

The way to connect to a network drive is pretty simple. You need to know the server name (or whatever computer is serving it up) as well as the name of the shared folder. Then, you can click Start and in the search box type \serversharename, where server is the name of the computer and sharename is the name of the shared folder. If the remote computer is online, and you have appropriate permissions, access will be granted to the resource.

It might be a pain to have to do this every time you want to access a network drive, so Windows and other operating systems give you the ability to map to a network drive and reconnect every time your computer boots up. In Windows, you click Start and right-click Computer. There you will have the option Map Network Drive. Click that, and it will open a screen similar to the one in Figure 6.5.

FIGURE 6.5 Mapping a network drive

When mapping a network drive, you first assign it a drive letter. It can be any letter you want that's not already in use on your computer. Then you type in the path to the folder or browse for it on the network. Finally, you can choose to reconnect at logon, and you can also use different credentials (username and password) to log on versus the ones you used to log onto your system. After you set your parameters, click Finish, and if you did everything right, you will now be able to access that shared resource. In fact, if you click Start Computer, that drive letter should now appear in your list of available drives. Exercise 6.1 has you practice doing this, but you will need access to a server or a second computer with a shared folder for this exercise to work.

Types of Local Sharing

Resources located on your computer or on a server somewhere aren't automatically available to other users on the network. This is a very good thing, because you probably have files that are private and no other users need to get to. Even on a server, there are files that no one has business getting to across the network. In order to make these resources available to users on different systems, you have to share them. After the resources are shared, the computer uses security permissions to determine who can get to the resources and what they can do once they get there, such as only read the file or make changes to the file.

Here, you will learn about two different types of sharing: peer-to-peer, which is designed more for ad hoc and temporary connections, and file and print sharing, which is usually more permanent in nature.

Peer-to-Peer Sharing

Based on its name, you can guess that peer-to-peer (P2P) sharing does not involve the use of servers. Both computers or mobile devices used in this arrangement are peers. One will serve the material to the other but does not have any other predetermined higher level of importance.

Ad Hoc Bluetooth Sharing

For mobile devices, Bluetooth sharing can be a quick and easy way to transfer files—most often pictures, videos, or contacts—from one device to another. As you learned earlier in this chapter, when two Bluetooth-enabled devices are close enough to each other, they can automatically create a network called a piconet.

To transfer files between devices, though, you need an app. Each mobile's app store will have plenty of options to choose from, so go with the one you like. Figure 6.6 shows a few popular options from the iTunes store.

After downloading the app, transferring files is pretty simple. Although the specific steps might differ based on your platform, this is generally how you do it:

1. Get in range of the other person with the Bluetooth-enabled device.
2. Open the app and locate their device.
3. Find the picture or file you want to share, tap it, and tap Share.
4. Choose Bluetooth as your sharing medium.
5. The person on the receiving end accepts the file.

FIGURE 6.6 Bluetooth sharing apps on iTunes

Once you've finished, you can close the app, turn off Bluetooth, and go about your day.

PC-to-PC Direct Link

This is the simplest of PC-based networks, because it involves only two computers directly connected to each other. A direct link network is typically used only for temporary situations. If you want a more permanent network, it's best to use a connectivity device like a hub or wireless router.

You have a few options to directly connect the PCs together. The first is to use a network cable with RJ-45 connectors. An ordinary network cable (called a patch cable) will not work, though; you need a crossover cable. Here's why. On a normal Cat 5 patch cable, four wires are used: 1, 2, 3, and 6. The wires, of course, connect to the pins on the connector in the network card. Pins 1 and 2 send data, and pins 3 and 6 receive data. If you were to try using a regular patch cable, the first computer would send data out pins 1 and 2 and straight to pins 1 and 2 (the send pins) of the second computer. That won't work. Instead, the crossover cable flips pins 1 and 3 and pins 2 and 6 on one end of the cable. That way the signals sent from one end get to the receiving pins on the other end. The second option is to use a direct-link USB cable.

After you connect the two computers, you need to share the directory or drive on the host computer that you want to access from the client computer. I will show you how to do that later in the “File and Print Sharing” section.

Online Peer-to-Peer Network

The PC-to-PC direct link solution works only if both computers are in the same location. If not, it can be hard to make the cable reach from one to the other. Fortunately there are online solutions that allow you to create an online P2P network to share movies, music, games, and other files.

P2P networks have existed since the late 1990s and have at times attained controversial status. One of the earlier examples of an online P2P network was Napster, which was set up to share music files. It worked by having users indicate which music files they wanted to share, and other users could search for music they wanted. The Napster servers indexed the content to make searching easier. After a match was made, the two computers were connected directly to each other for the file transfer.

The upside for users was that Napster allowed them to get music for free from other users. The downside, according to the music industry, was that it was illegal. After a series of lawsuits, Napster was shut down as a free service. Other services followed, which allowed for transfer of files other than music as well.

For business purposes, you can find several online tools that let you make a connection to another computer on the Internet to exchange files. Examples include JustBeamIt and FilesOverMiles. Others also exist that require you to download their client software onto your computer, such as BitTorrent.

Here are a few things to watch out for with online P2P networks:

• Make sure your security software is current. P2P apps can easily download malware to your computer.
• Related to that, always scan your downloads for viruses.
• Observe the laws. Don't download anything illegal or upload anything that you don't own the legally transferrable copyright to.
• Be careful which folders and files you share. You don't want your private information on display on the Internet. That's almost like asking to have your identity stolen.
• Close down the P2P session after you have finished to reduce your security risks.

If you are transferring work-related files between two computers, also be aware of potential security risks. The files and the transfers might or might not be encrypted, so it isn't the best idea to transfer secret information this way. Online P2P networks can be fast, but if you have any concerns about security or malware, just don't use them.

File and Print Sharing

Unlike P2P connections, setting up file and print sharing implies a longer-term connection. It also lets you make connections between more than two devices at a time. With file and print sharing, you can make folders or printers available to everyone in your office or all members of your family. There are two different ways I will talk about sharing resources here: using workgroups and using homegroups.

Configuring Workgroups for Sharing

Before I get too far into configuring a workgroup, I should stop for a minute and define what one is. A workgroup is a collection of peer-to-peer computers without centralized security. The limit you will see in Microsoft literature is that they are limited to 20 computers, but realistically anything more than 10 is too cumbersome to manage. Other features of workgroups include the following:

• To join the workgroup, only the workgroup name is required. No password is needed.
• Clients with various operating systems can join, such as any version of Windows and Mac OS X.
• Every computer on the workgroup needs to manage its own set of user accounts. This is one reason why administration becomes challenging.
• Every computer shares the resources it needs to share. This is another reason why administration becomes challenging.
• All computers must be on the same local network.

By default, your Windows computer will join the default workgroup, conveniently named WORKGROUP. You can see your system's workgroup configuration by going to Control Panel System And Security System (Figure 6.7). To change the workgroup name, you click Change Settings, which brings up the System Properties window, and then click the Change button to rename the computer or the workgroup (Figure 6.8).

Because there is no password required, it's quite easy to join a workgroup. That can also be a bad thing, because you can't stop a local computer on your network from joining the workgroup if you don't want it to. Macs can join workgroups as well; Exercise 6.2 shows you how.

FIGURE 6.7 Workgroup name

FIGURE 6.8 Changing the computer and workgroup name

GRANTING ACCESS TO SHARED RESOURCES

Granting access to a resource involves two steps: sharing the resource and assigning permissions. To share a folder, right-click the folder in Windows Explorer, choose Properties, and click the Security tab, as shown in Figure 6.9.

Clicking Advanced Sharing will bring up the Advanced Sharing window (Figure 6.10), and here is where you check the box to share the folder, give it a share name (it doesn't need to be the same as the folder name), and limit the number of concurrent users if you choose to. Also, you can click the Permissions button to set access restrictions on the folder (Figure 6.11). You'll see in Figure 6.11 that by default, the Everyone group has Read access to this folder. This raises two questions. One, who is Everyone, and two, what do the three permissions mean?

Everyone means every person who has an account on this local computer. Keep in mind that we are still talking about accessing a shared resource across the network. This means that in your workgroup of 12 people, if you have a folder that everyone needs, you need to have user accounts for all 12 of those people on your computer. If the user accounts don't exist, you need to create them. If a user changes his password on one computer, it won't change on yours. Can that get confusing? You bet it can. Playing this out even further, you can imagine how fun this scenario gets when everyone has resources to share. Twelve workstations with 12 accounts each means 144 user accounts in total.

There is a way around that, but it's not recommended because it weakens your security. If you look back at the Sharing tab shown in Figure 6.9, you will see a link at the bottom of the window for the Network and Sharing Center. Click that, and then click the down arrow across from Home Or Work. It will open up a screen like the one shown in Figure 6.12. Here you have an option called Password Protected Sharing. If you turn this off, then people don't need a user account on your system to access files. It will make your life easier, but it's not recommended. Remember, people don't need passwords to join your workgroup. They only need to be on the local network, which could mean they are sitting in the parking lot (in a black car with dark tinted windows), using their laptop, and connecting via your wireless network.

FIGURE 6.9 Sharing tab

As for the second question, there are three share permissions: Full Control, Modify, and Read. Here's what they allow:

• Full Control allows the user to do anything to the folder, its files, and subfolders, including deleting them all, changing permissions, and giving themselves ownership.
• Modify lets the user do almost everything Full Control does, except users can't change permissions, delete subfolders or files, or give themselves ownership.
• Read lets the user read the contents of the file or folder or execute an application.

FIGURE 6.10 Advanced Sharing window

FIGURE 6.11 Sharing permissions

FIGURE 6.12 Network and Sharing Center

Once the resource is shared, users on the network can access it by clicking Start and in the search box typing \serversharename, where server is the name of the computer and sharename is the name of the shared folder. Or, they can find it by clicking Start Computer (or opening any Windows Explorer window) and then looking under the Network heading in the left navigation pane.

SHARING PRINTERS

Sharing a printer in a workgroup is similar to sharing a folder; you just need to locate the printer instead of the folder to share. Exercise 6.3 walks you through sharing a printer.

There are two different ways printers can be attached to the network: they can connect to your local computer using a USB cable, or they can connect to the network directly with a network cable or wireless.

If the printer is connected to your machine, users need an account on your computer to use it, just as they would for shared files. In addition, if your computer is off for any reason, the printer is not available. Finally, clients using tablets or smartphones will not be able to print to the printer. Connecting directly to the network is much easier. Your computer can be off yet others can still print, and mobile users will be able to print as well. Networked printers are typically shared through their own interface (most will have their own touchscreen display) as opposed to through a workstation.

Sharing in Homegroups

A homegroup is a group of computers on a home network that can share files and printers. It sounds a lot like a workgroup, doesn't it? In some ways they are analogous, but there are some major differences. Microsoft introduced homegroups in Windows 7, and only Microsoft Windows 7 and newer operating systems can participate in them. In addition, homegroups have the following features:

• An unlimited number of computers can join.
• A password is required to join the homegroup.
• Members do not need to be on the local network.
• IP version 6 is required.
• Sharing files and printers is easier than sharing them in a workgroup.

How do you know if you are in a homegroup? First, if you are not running Windows 7 or newer, then the answer is easy: no, you're not. If you are running Windows 7 (or newer), you can open Control Panel Network And Internet Network And Sharing Center (Figure 6.14) and look at the screen. Next to the network connection, it will say HomeGroup: Joined. If it says anything else, you are not in a homegroup.

Changing homegroup settings or sharing resources is easily accomplished by going to the HomeGroup page shown in Figure 6.15. You can get there by clicking the Joined link in Figure 6.14, clicking HomeGroup in the Network and Sharing Center, or by choosing HomeGroup from Control Panel Network And Internet.

In Figure 6.15, you can see that you just check boxes to share or stream data, and you have links to view and change the homegroup password, leave the homegroup, change advanced settings, or troubleshoot problems. The best part is that unlike a workgroup, the users in your homegroup don't need accounts on your computer to access files, so network administration is a lot easier.

FIGURE 6.14 Member of a homegroup

FIGURE 6.15 HomeGroup settings

If you don't want to share all of the files on your computer with members of your homegroup, you can stop sharing of specific folders. Stopping the sharing affects files in that folder as well as any subfolders. To do that, find the folder you want to stop sharing, right-click, and choose Share With Nobody, as shown in Figure 6.16. Or, you can choose to share only with Specific People, and then you are essentially back to managing user accounts just as you would with workgroup sharing.

FIGURE 6.16 Share with Nobody

Web-Based Sharing and Access

Sharing and accessing resources across the Web bears very little resemblance to sharing resources locally. The concept is the same—an administrator makes a resource available and a client user accesses it—but the way in which it's accomplished is quite different.

At the same time, you are probably very used to accessing resources over the Web. It's likely that you are on the Internet every day, or at least a few times a week, and when you are, you're accessing resources across the Web. It might be as simple as reading about news or celebrities or sports, or it might be downloading a new application for your computer.

This section is broken into two parts. In the first, I will talk about concepts related to cloud computing and demystify what it really means. In the second, I will cover specific methods and protocols used to access resources across the Internet.

Cloud Concepts

You hear the term a lot today—the cloud. What exactly is the cloud? The way it's named, and it's probably due to the word the at the beginning, it sounds like it's one giant, fluffy, magical entity that does everything you could ever want a computer to do. Only it's not quite that big, fluffy, magical, or even one thing.

Cloud computing is a method by which you access remote servers to store files or run applications for you. There isn't one cloud but hundreds of commercial clouds in existence today. Many of them are owned by big companies such as Microsoft, Google, HP, Apple, Netflix, Amazon, and others. Basically, they set up the hardware and/or software for you on their network, and then you use it.

Using the cloud sounds pretty simple, and in most cases it is. From the administrator's side, things can be a little trickier. Cloud computing uses a concept called virtualization, which means there isn't necessarily a one-to-one relationship between a physical server and a logical (or virtual) server. In other words, you might have one physical server that virtually hosts cloud servers for a dozen companies, or you might have several physical servers working together as one logical server. From the end user's side, the idea of a physical machine versus a virtual machine doesn't even come into play, because it's all handled behind the scenes.

Cloud providers generally offer one of three types of services:

Software as a Service (SaaS) SaaS handles the task of managing software and its deployment. This is the one you are probably most familiar with, because it's the model used by Google Docs, Microsoft Office 365, and even storage solutions such as Dropbox. The advantage of this model is to cut costs for software ownership and management; usually you sign up for subscriptions to use the software.

Platform as a Service (PaaS) PaaS can be very helpful to software developers, because the vendor manages the various hardware platforms. This frees up the software developer to focus on building their application and scaling it.

Infrastructure as a Service (IaaS) Let's say you need extra network capacity, including processing power, storage, and networking services (such as firewalls), but you don't have the money to buy more network hardware. Instead, you can purchase IaaS, which is a lot like paying for utilities—you pay for what you use. Of the three, IaaS requires the most network management expertise from the client.

Running a cloud is not restricted to big companies over the Internet either. You can purchase virtualization software to set up your own cloud within your own network. That type of setup is referred to as a private cloud, as opposed to the public clouds I mentioned earlier.

The upside of using a cloud is that it's generally cheaper than needing to buy your own hardware or software and install and manage it all. Plus, if there is a hardware failure within the cloud, the provider handles it for you. If the cloud is set up right, you won't even know a failure occurred. The biggest downside has been security. You're storing your data on someone else's server and sending it back and forth via the Internet. Cloud providers have dramatically increased their security over the last few years, but this can still be an issue, especially if you are dealing with highly sensitive material or personally identifiable information (PII).

Cloud-Based Storage

Storage is the area in which cloud computing got its start. The idea is simple—you store files just like you would on a hard drive but with two major advantages. One, you don't need to buy the hardware. Two, users can access the files regardless of where they are physically located. You can have users in the United States, China, and Germany, and all of them have access via their web browser.

There is no shortage of cloud-based storage providers on the market today. Each one offers slightly different features. Most of them will offer limited storage for free and premium services for more data-heavy users. Table 6.1 shows you a comparison of some of the more well-known providers. Please note that the data limits and cost can change; this is for illustrative purposes only. Most of these providers offer business plans with unlimited storage as well, for an additional cost.

TABLE 6.1 Cloud providers and features

Which one should you choose? If you want extra features such as web-based applications, then Google or Microsoft is probably the best choice. If you just need data storage, then Box or Dropbox might be a better option.

Most cloud storage providers offer synchronization to the desktop, which makes it so you have a folder on your computer, just as if it were on your hard drive. And importantly, that folder will always have the most current edition of the files stored in the cloud.

Accessing the sites is done through your web browser. Once you are in the site, managing your files is much like managing them on your local computer. In Figure 6.17 you can see the Google Drive interface, with three folders and two files in it.

You have a few options to share a folder with another user. One way is to right-click the folder and choose Share Share (Figure 6.18). You'll be asked to enter their name or email address and indicate whether they can view or edit the file. To share multiple items, you can check the boxes in front of folder names (as the box is checked in Figure 6.18) and then click the icon that shows a person and a plus sign right above the check box. That will take you to the same sharing menu, which asks for the name and email address.

FIGURE 6.17 Google Drive

FIGURE 6.18 Sharing a folder on Google Drive

Cloud-Based Applications

Google really popularized the use of web-based applications. After all, the whole Chromebook platform, which has been very successful, is based on this premise! Other companies have gotten into the cloud-based application space as well, such as Microsoft with Office 365. The menus and layout are slightly different than PC-based versions of Office, but if you're familiar with Office, you can easily use Office 365. And, all of the files are stored on the cloud.

Cloud-based apps run through your web browser. This is great for end users for a few reasons. One, your system does not have to use its own hardware to run the application. Two, different client OSs can run the application (usually) without worrying about compatibility issues.

To create a new document using Google Docs, you click the Create button shown on the left side of Figure 6.18 and then choose Document from the menu. It opens a new browser window with Google Docs, shown in Figure 6.19.

FIGURE 6.19 Google Docs

The newest trend in web applications and cloud storage is the streaming of media. Companies such as Netflix, Amazon, Pandora, and others store movies and music on their clouds. You download their client software, and for a monthly subscription fee you can stream media to your device. It can be your phone, your computer, or your home entertainment system. Before the advent of broadband network technologies, this type of setup would have been impossible, but now it is poised to become the mainstream way that people receive audio and video entertainment.

Accessing Web-Based Resources

Browsing the Internet is something you probably do most days of the week, so spending time here telling you how to do that isn't the most productive thing to do. Instead, I will talk about some of the things that are going on behind the scenes, so you understand what's really happening.

First, remember that everything on the Internet revolves around TCP/IP, which you learned about in Chapter 5. If you'll recall, accessing another computer on the Internet requires knowing the remote computer's IP address. Think of it in terms of delivering a package. If you tell the driver to deliver the package to James White, and that's all you tell him, you will probably get a blank stare. But if you tell the driver that James White lives at 123 Main Street in Buffalo, New York, then the driver knows where to go. DNS servers help out a lot, because they resolve host names to IP addresses. Summarizing the process of accessing an Internet site looks something like this:

1. You open your web browser, type in www.google.com, and press Enter.
2. Your computer looks to find the IP address of a DNS server. If there is no DNS server configured, you will get a message that the server cannot be found. If you do have a DNS server configured, your system will ask the DNS server for the address to www.google.com.
3. The DNS server replies that www.google.com is 173.194.219.99.
4. Your computer sends a message to 173.194.219.99 (via your router) asking to make a connection.
5. The server at 173.194.219.99 responds with its content, which is the file set up as its default home page.

The actual process is a bit more complicated, but this covers the most important parts. One thing I need to add to it, though, is the use of ports. Think of a port as a communications channel. It's like cable television. You get 500 channels delivered to your address, but when you want to watch a show you need to turn to a specific channel. The same sort of thing happens on the Internet. When you make the connection to 173.194.219.99, you do it using the appropriate port (channel) for the request. For example, normal web browsing uses HTTP on port 80. So technically you are communicating to 173.194.219.99:80. The combination of the IP address and port number is called a socket. Ports let servers differentiate and keep track of incoming and outgoing traffic for better data management.

Web Browsing

The TCP/IP protocol used the most often, by far, is the Hypertext Transfer Protocol (HTTP). It's used to manage communications between web browsers and web servers, and it opens the right resource when you click a link. HTTP is optimized to deliver text, graphics, and hyperlinks to other resources. As I mentioned in the previous paragraph, HTTP uses port 80.

While HTTP is a great, versatile protocol, it has one glaring weakness—it's unsecure. Fortunately, there is a solution for that, and it's Hypertext Transfer Protocol Secure (HTTPS). HTTPS connections are secured using either Secure Sockets Layer (SSL) or Transport Layer Security (TLS), and HTTPS uses port 443. If you want to access secure information online, such as personal banking or anything that has you type in a password, make sure the site is using HTTPS and not HTTP.

From the client side, the most common issue you will encounter when HTTPS is in use on a website is that users may not know what the proper context is. To access most websites, you use http:// in the address bar. To get to a site using HTTPS, you need to use https:// instead.

Exercise 6.4 shows you what to look for to verify that it's a secure site using HTTPS.

If you use your web browser to initiate a file download, it will process those requests (either in the background or overtly) using FTP, which I am going to cover next.

File Downloads

Just as HTTP is optimized for web traffic, the File Transfer Protocol (FTP) is optimized to do what it says it does—transfer files. This includes both uploading and downloading files from one host to another. FTP is both a protocol and an application. Specifically, FTP lets you copy files, list and manipulate directories, and view file contents. You can't use it to remotely execute applications. FTP uses ports 20 and 21.

Whenever a user attempts to access an FTP site, they will be asked for a login. If it's a public site, you can often just use the login name anonymous and then provide your email address as the password. Of course, there's no rule saying you have to give your real email address if you don't want to. If the FTP site is secured, you will need a legitimate login name and password to access it. If you are using a browser such as Internet Explorer to connect via FTP, the correct syntax in the address window is ftp://username:[email protected].

If you're used to the pictures and hyperlinks on web pages, you will probably be a bit disappointed by the Spartan look of FTP sites. Remember that FTP is designed for file transfers, so there really are no bells and whistles in the example shown in Figure 6.22. You will see directories and files. The directories contain sample images of files from the various books that Sybex has published over the last several years.

FIGURE 6.22 Sybex public FTP site

The only problem with FTP is that all data is sent in clear text, just like HTTP. If you need to make your FTP transfer secure, then you'll use SFTP. Secure File Transfer Protocol (SFTP), also called SSH File Transfer Protocol, is used when you need to transfer files over an encrypted connection. It uses a Secure Shell (SSH) session, which encrypts the connection on port 22. Apart from the secure part, it's used just as FTP is—for transferring files between computers on an IP network, such as the Internet.

The final option you should know about is File Transfer Protocol Secure (FTPS). It's like HTTPS in that it uses SSL or TLS to secure the connection. Because of this, it requires a third-party-issued security certificate, which is an extra step that most administrators don't want to deal with. In addition, it doesn't have as many features as SFTP. Honestly, I am kind of surprised that it's an exam objective because since the introduction of SFTP in 1997, it's hardly ever used in the real world. FTPS can run on port 990 or port 21.

Summary

In this chapter, you learned about sharing and accessing local and web-based resources. First, you learned about network types, such as LANs, WANs, PANs, and MANs, as well as the differences between client-server and peer-to-peer networking models. Then, you read about storage options such as direct attached storage and network attached storage and how to connect to network drives.

Next, you learned about different peer-to-peer sharing models. Examples included ad hoc Bluetooth networks, direct link peer-to-peer, and online peer-to-peer connections. Then the P2P model was expanded a bit to cover workgroups and homegroups and the differences between them. This included sharing printers.

Finally, you learned about web-based sharing and resource access. One of the hot buzzwords in computing today is the cloud. You learned that the cloud isn't a single thing but a collection of hardware and software that you can use for your storage and application needs. The chapter finished with a discussion on accessing web resources using HTTP and HTTPS, as well as transferring files with FTP, SFTP, and FTPS.

Exam Essentials

Know the difference between DAS and NAS. Direct attached storage means a hard drive attached to your computer, whether it's an internal or external drive. Network attached storage is a hard drive unit with file management software that's directly attached to the network with a network cable.

Understand the difference between a peer-to-peer network and a client-server network. In a peer-to-peer network, there is no centralized security, and all systems on the network are considered equals. Resources may be shared from any system. In a client-server network, you have centralized security and resource management.

Know the different types of peer-to-peer sharing methods. Options include ad hoc Bluetooth networks, direct link PC-to-PC, and online peer-to-peer networks.

Understand the difference between local and network printing. If the printer is connected directly to your computer, it's local. You can share your local printer for others on the network to use, but if your computer is off, no one can use it. A network printer is attached to the network and is easier to share among several users.

Know how cloud-based storage and applications work. Third-party companies supply the hardware and software. Storage solutions such as Google Drive and Dropbox let you store files for access by anyone in the world through their web browser. Cloud-based apps like Google Docs and Microsoft Office 365 let you run an application through your web browser without needing the software installed on your computer.

Know the protocols used to access web-based resources. The protocols for websites are HTTP and HTTPS. For file downloads, you would use FTP, FTPS, or SFTP.

Chapter 6 Lab

This lab gives you experience with using cloud-based storage and applications. You can use any cloud provider you like, and in fact, it's better if you experience the differences in how providers store files and let you manage and manipulate them. For this example, you will use Google Drive and its associated apps.

This lab will work best if you have someone to work with. For example, in a classroom setting you can partner with someone. If you are studying at home, you can create multiple accounts and get the same experience. You will just need to log off and on with your other account to see the shared files.

1. Open Google at www.google.com.
2. If you do not already have a Google account, you will need to create one. This will let you use their online apps and storage, as well as give you a Gmail account.
3. Once you're logged in, click the Apps icon in the upper-right corner. It's the one that has nine small squares (Figure 6.23).
4. In Apps, click Drive. This will open Google Drive, as shown in Figure 6.24.
5. Create a folder and share it with another account. Also create a document or spreadsheet using Google's online software. How easy or difficult was it?
6. Now access the resources that were shared for you. How easy or difficult was it?

Here are some questions based on Google Drive.

1. How do you create new files or folders?
2. How do you upload files or folders from your computer?

   FIGURE 6.23 Google icons

   

   FIGURE 6.24 Google Drive

   

3. How do you see your most recent activities performed?
4. How do you synchronize files with your hard drive?
5. If you need another app, how do you get one?
6. How do you see how much storage space you have used?
7. Where do you change your display language or time zone or update your Google profile?

Review Questions

1. Which of the following types of networks offers centralized security and resource administration?
   1. LAN
   2. WAN
   3. Peer-to-peer
   4. Client-server
2. Which of the following are required to join a homegroup? (Choose two.)
   1. All computers on the same local network
   2. A password
   3. File and print sharing enabled
   4. Windows 7 or newer
3. If you were setting up a network on one floor of an office building, what type of network would that most likely be?
   1. LAN
   2. WAN
   3. Peer-to-peer
   4. Client-server
4. You want to share files among six computers, all running Windows 8. You do not want to have to create user accounts for each user on all six computers. What should you use?
   1. Workgroup
   2. Homegroup
   3. Client-server
   4. Ad hoc network
5. What kind of network is specifically associated with Bluetooth devices?
   1. LAN
   2. WAN
   3. PAN
   4. MAN
6. You have shared a folder with Mary, another user on your network. What share permissions should you give her if you want her to be able to edit a file but not give access to others?
   1. Full control
   2. Modify
   3. Edit
   4. Read
7. Susan has configured a peer-to-peer network at her company with her four co-workers. Each co-worker will share vital files from their computer with everyone else in the workgroup. How many total user accounts are needed on this network?
   1. 5
   2. 10
   3. 20
   4. 25
8. Martha has a printer attached to her workstation with a USB cable. Monday morning she calls in sick and her computer is off. Which of the following is true?
   1. Other users will be able to print to the printer with no problems.
   2. Other users need to turn the printer on, and then they can print with no problems.
   3. Other users should map it as a network printer, and then they can print with no problems.
   4. Other users will not be able to print.
9. What type of network model is also called a domain?
   1. LAN
   2. WAN
   3. Peer-to-peer
   4. Client-server
10. Google Docs is an example of which type of cloud computing?
    1. SaaS
    2. IaaS
    3. PaaS
    4. GaaS
11. Your computer is quickly running out of hard drive space, and you need to transfer several large files from another computer to yours. You need a fast and cheap solution. What type of storage should you get?
    1. NAS
    2. DAS
    3. Network drive
    4. P2P
12. What is the secure file transfer protocol that uses SSH for security?
    1. FTPS
    2. SFTP
    3. HTTPS
    4. SHTTP
13. You need to map your R drive to a local server. What is the proper context to map a shared drive?
    1. \servernamesharename
    2. servernamesharename
    3. ::servernamesharename
    4. >servername>sharename
14. You want to reconnect to a shared folder on a server every time your laptop restarts. What do you need to configure?
    1. DAS
    2. NAS
    3. Network drive
    4. Cloud storage
15. Which of the following storage devices is an external hard drive with its own file management software?
    1. NAS
    2. DAS
    3. Network drive
    4. Cloud
16. Which technology refers to online storage, and means that there is not a one-to-one relationship between the hardware and the server?
    1. Cloud computing
    2. Virtualization
    3. Server farm
    4. Spanning
17. Michael needs to connect two PCs directly to each other for large file transfers. What options does he have? (Choose two.)
    1. Cat 5 crossover cable
    2. Cat 5 patch cable
    3. Cat 5 duplex cable
    4. USB direct link cable
18. Users on a network are complaining that they can't access web servers. External email is coming through fine, and someone was able to access a secure web server. Which port was most likely accidentally blocked on the firewall?
    1. 20
    2. 21
    3. 80
    4. 443
19. You have eight computers located in one office building and want to share resources among them. All computers are running Windows 7. What is the easiest option to configure to share files and folders?
    1. Workgroup
    2. Homegroup
    3. PAN
    4. LAN
20. HTTPS uses which of the following to secure its connection? (Select two.)
    1. SSSH
    2. TLS
    3. SSL
    4. HASH