Networking All-in-One For Dummies - Doug Lowe

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more clients than servers. For example, a network with ten clients can probably get by with one server, but larger networks will likely require more servers.

       In most networks, a clean line of demarcation exists between servers and clients. In other words, a computer functions as either a server or a client, not both. For the sake of an efficient network, a server can’t become a client, nor can a client become a server.

       Other (usually smaller) networks can be more evenhanded by allowing any computer in the network to be a server and allowing any computer to be both a server and a client at the same time.

      In most networks, a server computer is a server computer and nothing else. It’s dedicated to the sole task of providing shared resources, such as hard drives and printers, to be accessed by the network client computers. This type of server is a dedicated server because it can perform no other task than network services.

      Some smaller networks take an alternative approach by enabling any computer on the network to function as both a client and a server. Thus, any computer can share its printers and hard drives with other computers on the network. And while a computer is working as a server, you can still use that same computer for other functions, such as word processing. This type of network is a peer-to-peer network because all the computers are thought of as peers, or equals.

      Here are some points to ponder concerning the differences between dedicated-server networks and peer-to-peer networks while you’re walking the dog tomorrow morning:

       Peer-to-peer networking features are built into Windows. Thus, if your computer runs Windows, you don’t have to buy any additional software to turn your computer into a server. All you have to do is enable the Windows server features.

       The network server features that are built into Windows 10 (the most popular desktop operating system) aren’t particularly efficient because this version of Windows wasn’t designed primarily to be a network server. If you dedicate a computer to the task of being a full-time server, use a special server operating system rather than the standard Windows desktop operating system. A server operating system is specially designed to handle networking functions efficiently.The most commonly used server operating systems are the server versions of Windows. As of this writing, the current server version of Windows is Windows Server 2019. However, many companies still use the previous version (Windows Server 2016), and a few use even earlier versions such as Windows Server 2012 and 2008.Another popular server operating system is Linux. Linux is popular because it’s free. Linux requires more expertise to set up than Windows Server but is just as capable.

       Many networks are both peer-to-peer and dedicated-server networks at the same time. These networks haveAt least one server computer that runs a server operating system such as Windows Server 2019Client computers that use the server features of Windows 10 to share their resources with the network

        Besides being dedicated, your servers should also be sincere.

      To use a network, you don’t really have to know much about how it works. Still, you may feel a little bit better about using the network if you realize that it doesn’t work by voodoo. A network may seem like magic, but it isn’t. The following list describes the inner workings of a typical network:

       Network interface: Inside any computer attached to a network is a special electronic circuit called the network interface. The network interface has either an external jack into which you can plug a network cable — or, in the case of a wireless network interface, an antenna.

       Network cable: The network cable physically connects the computers. It plugs into the network interface card (NIC) on the back of your computer.The type of network cable most commonly used is twisted-pair cable, so named because it consists of several pairs of wires twisted together in a certain way. Twisted-pair cable superficially resembles telephone cable. However, appearances can be deceiving. Most phone systems are wired using a lower grade of cable that doesn’t work for networks.For the complete lowdown on networking cables, see Chapter 2 of this minibook. Network cable isn’t necessary when wireless networking is used. For more information about wireless networking, see Chapter 2 of this minibook.

       Network switch: Networks built with twisted-pair cabling require one or more switches. A switch is a box with a bunch of cable connectors. Each computer on the network is connected by cable to the switch. The switch, in turn, connects all the computers to each other.Most networks of more than a few dozen computers have more than one switch. In that case, the switches themselves are connected to each other with cable in a manner that allows all the computers to communicate with each other without regard to which switch they’re directly connected to. In the early days of twisted-pair networking, devices known as hubs were used rather than switches. The term hub is sometimes used to refer to switches, but true hubs went out of style sometime around the turn of the century.I explain much more about switches and hubs in Chapters 2 and 3 of this minibook.

       Wireless access points: In a wireless network, most cables and switches are moot. Instead, radio takes the place of cables. The device that enables a computer to connect wirelessly to a network is called a wireless access point. A WAP is a combination of a radio transmitter and a radio receiver and has an integrated wired network port. The WAP must be connected to the network via a cable, but it allows wireless devices such as laptops, tablets, and phones to connect wirelessly.

       Router: A device found in nearly all networks is a router, which is used to connect two networks — typically your internal network and the Internet. You’ll learn more about routers in Chapters 2 and 3 of this minibook.

       Firewall: A firewall is an essential component of any network that connects to the Internet. The firewall provides security features that help keep cybercriminals out of your network.In most cases, the function of a firewall is combined with the function of a router in a single device called a firewall router. This makes sense because the firewall is a security wall between two networks (usually the Internet and your internal network). So, the router component links the two networks, while the firewall component provides security.In home networks or small office networks, it’s also common to combine the functions of firewall, router, WAP, and switch into a single device that’s usually called a wireless router or a Wi-Fi router. When you purchase such a device, check to make sure it has adequate firewall features and the correct number of switch ports for your wired devices.

      In a small network such as the one that was shown in Figure 1-1, a wireless router combines the function of firewall, router, switch, and WAP. This arrangement is fine for very small networks, but when you exceed the wired switch capacity of the wireless router, you’ll need additional components.

Schematic illustration of a network with a wireless router and a switch.

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