Section 7.1. Networking Terminology | Windows XP in a Nutshell, Second Edition

7.1. Networking Terminology

Understanding networking terminology is essential to making sense of the software and hardware used to assemble a network. The following terms are used throughout this chapter, as well as in just about any conversation about networking:

Bandwidth

The capacity of a network connection to move information. If a network is capable of transferring data at 10 Mbps, and two users are simultaneously transferring large files, each will only have about 5 Mbps of bandwidth at their disposal. See "Hubs and switches," later in this list, for limitations.

Bluetooth

A short-range RF (radio frequency) wireless standard used to connect handheld devices and peripherals at speeds from 1 to 2 Mbps. Supported by industry heavyweights such as IBM, Intel, and Nokia, Bluetooth hasn't taken off yet. It's mostly shown up in mobile phones, although Bluetooth-capable GPS units, printers, mice, keyboards, and other devices that need to transmit modest amounts of data over short distances are on the market and gaining popularity. Windows XP only supports Bluetooth natively when Service Pack 2 is installed, adding a new Bluetooth Devices control panel that's only visible once you've installed a Bluetooth receiver. The notable feature: a Bluetooth wizard that makes it easy to connect new devices.

Bluetooth devices often use a "passkey" to connect to your computer. This is for "handshaking" rather than security purposes, ensuring that your mouse won't suddenly start controlling your office mate's cursor. One security measure: Before any Bluetooth device can be connected to your PC, you must first check the "Turn discovery on" box in the Bluetooth Control Panel and then configure your Bluetooth device to be "discoverable." Once a new device is added, it can connect to your PC at any time, even if the " Turn discovery on" box is later unchecked.

Your connections can be encryptedif your applications and drivers provide it. Due to Bluetooth's relatively short range, there's not a lot that passersby can do, although hacker kids have risen to the challenge with "bluejacking," sending secret messages to victims' phones. You can prevent this by turning off discovery mode, ensuring that only devices you've specifically configured to work with your device can talk to it.

Ethernet

The technology upon which the vast majority of local area networks is built. A standard Ethernet connection is capable of transferring data at a maximum of 10 Mbps, and a Fast Ethernet connection can transfer data at 100 Mbps. A device capable of communicating of both speeds is typically labelled "10/100."

Firewall

A layer of protection that permits or denies network communication based on a predefined set of rules. A firewall can be used to restrict unauthorized access from intruders, close backdoors opened by viruses and other malicious applications, and eliminate wasted bandwidth by blocking certain types of network applications. Windows XP includes a rudimentary firewall feature, described in Section 7.2.5, later in this chapter.

Hubs and switches

Devices on your network to which multiple Ethernet connections (called nodes ) are made. See Figure 7-1 for an example. The main difference between a hub and a switch is a matter of performance (and cost). A switch is capable of handling multiple, simultaneous, full-bandwidth connections, while the less expensive hub throttles all connections such that, for example, three simultaneous connections can only each use one third of the total bandwidth.

IP address

A set of four numbers (e.g., 207.46.230.218 ) corresponding to a single computer or device on a TCP/IP network. No two computers on a single network can have the same IP address, but a single computer can have multiple IP addresses. Each element of the address can range from 0 to 255, providing 256^4 or nearly 4.3 billion possible combinations. Network Address Translation (NAT) is used to translate an address from one network to another. This is useful, for example, when a LAN is connected to the Internet. On the Internet, dedicated machines called nameservers are used to translate named hosts , such as www.microsoft.com, to their respective numerical IP addresses. See "Windows IP Configuration" and "NSLookup", both in Chapter 4, for more information.

LAN

Local Area Network, a designation typically referring to a network contained in a single room or building.

Mbps

Megabits per second, the unit of measure used to describe the speed of a network connection. Ethernet-based networks can transfer data either up to 10 Mbps or up to 100 Mbps. High-speed T1, DSL, and cable modem connections typically transfer data up to 1.5 Mbps, while the fastest analog modems communicate at a glacial 56 kbps, or 0.056 Mbps.

Since there are eight bits to a byte, you can determine the theoretical maximum data transfer rate of a connection by simply dividing by 8. For example, a 384 kbps connection transfers 384 / 8 = 48 KB of data per second, which should allow you to transfer a 1 MB file in a little more than 20 seconds. However, there is more going on than just data transfer (such as error correction), so actual performance will always be slower than the theoretical maximum.

NIC

Network Interface Card, commonly known as an Ethernet Adapter. If your computer doesn't have built-in Ethernet, you'll need a NIC to connect your computer to a network. For Desktops, your NIC should be a PCI card; for laptops, your NIC should be a PCMCIA (PC Card) card. Universal Serial Bus (USB) based NICs can also be used with both desktops and laptops.

Ports

A number representing the type of communication to initiate. For example, web browsers typically use port 80 to download web pages, so web servers must be "listening" at port 80. Other commonly used ports include port 25 for sending email (SMTP), port 110 for retrieving email (POP3), port 443 for accessing secure web pages, port 21 for FTP, port 23 for Telnet, port 22 for SSH, port 53 for DNS, port 119 for newsgroups, and port 6699 for peer-to-peer file sharing applications (such as Napster).

PPP

Point-to-Point Protocol, a protocol used to facilitate a TCP/IP connection over long distances. PPP is used by Windows to provide an Internet connection over ordinary phone lines using an analog modem. Some DSL and cable connections use PPPoE (PPP over Ethernet), discussed later in this chapter.

Protocol

A protocol is the language, so to speak, that your computer uses to communicate with other computers on the network. These days, the TCP/IP set of protocols is the de-facto standard for local area networks, and is required for Internet connections.

TCP/IP

Shorthand notation for the collection of protocols that includes Transmission Control Protocol (TCP), Internet Protocol (IP), User Datagram Protocol (UDP), and Internet Control Message Protocol (ICMP). TCP/IP is required for all Internet connections, and is the standard protocol for most types of modern LANs.

Topology

The physical layout of your network. See the next section, Section 7.1.1, for more information on how topology comes into play.

WAN

Wide Area Network, or a network formed by connecting computers over large distances. The Internet is an example of a WAN.

Wi-Fi (802.11x)

The current standard(s) for wireless networking. The 802.11x series isn't one technology, but several. But when we talk about Wi-Fi connections, we usually mean 802.11bthe current worldwide standard, especially for home networks, which offers transmission speeds up to 11 Mbps. Its successor, 802.11g, boosts the maximum throughput to 54 Mbps while maintaining backward compatibility with 802.11b. (Also on the market is 802.11a, although its limited range and lack of compatibility with the "b" and "g" standards make it a poor choice for most Wi-Fi nuts.)

These standards include encryption to keep your data secure and to make sure that only authorized computers are able to connect. The most common method is WEP (Wired Equipment Privacy), although its successor WPA (Wi-Fi Protected Access), a subset of technology that will appear with the forthcoming 802.11i) offers increased security. But both protocols are fairly easy to crack and shouldn't be used for mission-critical data.

A wireless network typically consists of a wireless router (the access point) connected to the Internet via broadband, and one or more computers that can tap into the router. (You can have a wireless network without a wireless router using "ad hoc" mode, but only between two computers at a time.) Most new laptops come with Wi-Fi support built in, although desktop PCs may require a wireless PCI card or USB adapter.

Wireless networking is easy to set up, but can be more challenging to run, and securing a wireless network can be a pain.

Fortunately, Windows XP can access any Wi-Fi connection out of the box, if you have the necessary security keys. Service Pack 1 attempted to promote security by making it harder to access unprotected networks, which proved extremely annoying. Service Pack 2 (discussed in Appendix H), warns you if a network is insecure , but otherwise lets you connect to it without quibbling. Beyond home and business use, public Wi-Fi networks or "hotspots" are showing up in airports, coffee houses , libraries, and other public places. Some of these hotspots offer free access; others charge. For hotspots near you, check out http://www.wi-fihotspotlist.com.

Workgroup

Another name for a peer-to-peer LAN.

7.1.1. Planning Your Network

There are many types of networks, but for the purposes of this chapter, we will be focusing on three basic categories.

Peer-to-Peer Local Area Network (LAN): A LAN is the connection of two or more computers in close proximity, typically in the same building or room. The term "peer-to-peer" implies that each of the computers on the network will have pretty much the same role. This is in contrast to a client/server setup, in which certain computers are intended solely to store data, handle printing, or manage user accounts.
Wireless Networking: Wireless Networking typically refers to Wi-Fi, or 802.11x for short. The most common variety used in home networks is 802.11b, although many people are moving up to the faster 802.11g standard.
Connection to the Internet: By connecting your computer to the Internet, you are networking your machine to the world's largest Wide Area Network (WAN).

Now, as far as Windows XP is concerned there is very little difference between these two types of network connections. The distinction is made primarily to help you visualize the topology of your environment. See Figure 7-1, Figure 7-2, and Figure 7-3 for some example setups.

Figure 7-1. A simple network with four computers connected with a hub (or switch), one printer connected to one of the computers, and no Internet connection

Figure 7-2. A simple network with three computers, one of which has an Internet connection that can be shared; see Section 7.2.4, later in this chapter, for details

Figure 7-3. A simple network with three computers connected to a hub or router; see "Internet connection sharing," later in this chapter, for details

An especially interesting application of these technologies is how they can be mixed and matched. For example, you can connect your LAN to the Internet using Internet Connection Sharing, giving Internet access to everyone on your local network. Or, you can simulate a LAN over an Internet connection using Virtual Private Networking.

Here are some things to consider when planning your network:

Wiring can be time consuming and frustrating. Drawing a diagram of the physical layout of the computers and devices on your network can help you visualize the topology and plan the cables, hubs, and other devices required. For example, if two more users are to share a printer, make sure the printer is in a convenient , central location.
Wireless networking is a reality, but it is more expensive and not as fast as a wired connection. Whether the cost is worth the convenience depends on what you're using it for. For example, a IEEE 802.11b-compliant wireless network transfers data up to 5 Mbps, which is plenty for a 1.5 Mbps Internet connection, but may not be adequate for transferring large amounts of data when compared with a 100 Mbps connection.
It's also important to realize that you don't have to commit solely to one technology or another. For instance, you can mix and match wireless and wired networks, which may mean only purchasing wireless equipment for laptops, or those computers that would otherwise be very difficult to wire.
When assigning roles to different computers, think about how often they'll be used. For example, a computer that provides an Internet connection for your network must be on for the connection to be active, so it's best to hook up your Internet connection to the computer that is most likely to be turned on at any given time. And a computer hosting a shared printer or shared files will not only need to be turned on, but should also be a fast system with lots of memory so that it can handle the extra load.
Windows XP includes firewall and Internet connection-sharing functionality right out of the box, but these can be somewhat limited when compared with extra-cost hardware alternatives.
Some printers can be hooked up directly to the network, eliminating the need for a dedicated computer to host them. While this typically adds cost, it means that any computer on the network can print without first having to turn on another computer. If this option is not available for your printer, you can still hook it up to a separate print server device.

7.1.2. Configuring Network Connections

The central interface used to configure the networking features in Windows XP is the Network Connections window, introduced in Chapter 4. Right-click the My Network Places icon on your Desktop and select Properties, or use Control Panel [Network and Internet Connections] Network Connections to open the Network Connections Window.

Figures Figure 7-4 and Figure 7-5 show two different views of the Network Connections window. Depending on your Windows Explorer settings (discussed in Chapters Chapter 3 and Chapter 4), your view may be different, but all the required components are still there. If you haven't done so already, select Details from the View menu to see all the pertinent information.

Figure 7-4. If common tasks (Tools Folder Options) are enabled, the Network Setup Wizard and New Connection wizard are accessible through the tasks pane on your left

Figure 7-5. If common tasks are not shown, the Network Setup Wizard and New Connection Wizard appear as icons in your Network Connections window

As its name implies, Network Connections lists all of the networking connections configured on your computer. Windows doesn't care how many computers are on your network, whether you're using a hub or a switch, or even what type of cabling you've used. Rather, the only thing you need to worry about in the context of this window is the individual connections attached to this computer.

In Figures Figure 7-4 and Figure 7-5, two network connections are shown, one for each network adapter installed in the machine. In the right-hand computer in Figure 7-2, a dotted rectangle shows the same setup graphically. Here, we have a single computer with two networking connections: one used to connect to the Internet, and one used to connect to the hub and the rest of the LAN. (See Section 7.2.4, later in this chapter, for more information on why two connections are required to share an Internet connection with the other computers on a LAN.)

You should have a connection icon for each network adapter (NIC) installed in your system; install a new network adapter, and (if properly installed) it will show up automatically in the Network Connections window. You might also have one or more connection icons for so-called "soft" connections, such as dial-up connections (for your analog or ISDN modem), PPPoE connections (for certain types of DSL and cable modems), and Virtual Private Networking (VPN) connections.

To add a new connection (all types except those that correspond to physical network adapters), open the New Connection Wizard (or click Create a new connection if you have the Common Tasks pane enabled). See "New Connection Wizard" in Chapter 4 for more information on this feature. Throughout the rest of this chapter, you'll see several examples of how and when this wizard is used.

A similar-sounding feature, called the Network Setup Wizard (click "Set up a home or small office network" if you have the Common Tasks pane enabled), is used to automatically configure your Internet connection and local network settings based on one of several predefined scenarios. See "Network Setup Wizard" as well as several sections throughout the rest of this chapter for more details.

Right-click a connection icon and select Properties to configure any existing network connection. Depending on the type of connection, you'll see one of several different types of Properties sheets.

7.1.2.1 LAN or High-Speed Internet connection properties

The Properties window for LAN or High-Speed Internet connections is divided into three tabs: General (as shown in Figure 7-6), Authentication, and Advanced (as shown in Figure 7-7).

Figure 7-6. The Authentication Tab allows you to set security features

Figure 7-7. The Advanced tab controls the firewall and Internet Connection Sharing

The use of these tabs is as follows :

General

The General tab allows you to configure the main aspects of the connection. The Connect using box shows the hardware adapter with which this connection is associated; click Configure to open the device's properties window, which is the same one you'll get through Device Manager (see Chapter 4).

Next is the list of installed networking components; the checked items represent the services and protocols to be used with the connection. See "Protocols and Services," later in this chapter, for details.

Finally, the "Show icon in notification area when connected" option allows you to toggle the tray icon; if the connection is always active, you can reduce clutter by turning this off.

Authentication

The settings on this page are used to implement certain security features, mostly used in conjunction with wireless networks. Most users will never need to adjust these settings. If you have a wireless network, and you're concerned about unauthorized users accessing your network with their own wireless equipment, look up "Authentication" in the Help and Support Center. (See Chapter 4 for more information.)

Advanced

The Advanced settings are simple, but powerful. These options allow you to control the Internet Connection Firewall and Internet Connection Sharing, both discussed later in this chapter.

7.1.2.2 Dial-up/ Broadband connection properties

For dial-up broadband connections (such as PPPoE), the Properties window (shown in Figure 7-7) has the following tabbed pages:

General

The General tab allows you to configure the main aspects of the connection.

The Connect using box (Dial-Up connections only) shows the currently selected modem; click Configure to open the device's properties window, which is the same one you'll get through Device Manager (see Chapter 4). Below, you can change the phone number or even add additional phone numbers, through which Windows will cycle if the first one is busy or unavailable.

The Service name box (Broadband connections only) should be left blank, unless instructed otherwise by your service provider.

Finally, the "Show icon in notification area when connected" option allows you to toggle the tray icon; turning this option on will allow you to disconnect the connection more easily (by right-clicking on the tray icon).

Options

The settings in the Options page affect dialing properties, such as when and how many times to redial, and whether Windows should prompt for information before attempting a connection.

Security

The Security settings allow you to control how your username and password are transmitted to the server; most users will want to leave these settings unchanged. Contact your service provider for more information on supported security protocols.

Networking

The first box is a drop-down list containing all of the supported connection types for the connection. For dial-up connections, you'll usually want PPP; for broadband connections, you'll usually want PPPoE. Like some of the other settings in this window, your service provider will inform you if you need to change any of these settings.

Advanced

The Advanced tab is the same as the Advanced tab for standard network connections; these options allow you to control the Internet Connection Firewall and Internet Connection Sharing, both discussed later in this chapter.

7.1.2.3 Wireless connection properties

Provided that you have the hardware, and a suitable connection, Windows XP is capable of handling most Wi-Fi network settings for you. Should anything go wrong, or if Windows detects new networks it can connect to, it alerts you via a pop-up in the System Tray.

To see all available networks, right-click the wireless connection icon in the System Tray and select View All Available Wireless Networks, or click the View Wireless Networks button in the connection's Status window. You'll get a list showing all the network names and if they're open or secured. If Service Pack 2 is installed, you can simply select the network that you want to connect to and enter its WEP key if required

7.1.2.3.1 Wireless Network Connection window

A major addition with Service Pack 2, the Wireless Network Connection window provides a friendly view of all the available wireless networks in your vicinity, complete with status information. You'll see each network's name (such as "oreillynet"), and either "Unsecured wireless network" or "Security-enabled wireless network" (complete with a tiny padlock icon, and a warning that you'll need a network key to connect to it, if you haven't already).

On the right, a mobile phone-style set of bars offers an at-a-glance view of how strong each connection is, and any important status information (including "Acquiring network address" while connecting, or "Limited or no connectivity"). If the latter is underlined , click it to summon information on what went wrong and how you can make things right.

To connect to any network, double-click its entry or select it from the list and click the Connect button at the bottom. A dialog box will automatically appear if you need to enter a WEP key.

On the left of the screen are shortcuts to all the main wireless networking controls (see Figure 7-8). In Network Tasks, "Refresh network list" re- scans for any changes to available networks, while "Set up a wireless network for a home or small office" displays the Wireless Network Setup Wizard. Related Tasks offers three options. "Learn about wireless networking" displays relevant entries in the Help and Support Center; while "Change the order of preferred networks" and "Change advanced settings" both open the Wireless Network Connection Properties window, on the General and Wireless Networking tabs, respectively.

Figure 7-8. From the new Wireless Network Connection window, you can connect to available networks with a click, check signal strength, and more

7.1.2.3.2 Wireless connection icon

Double-click the wireless connection icon in the System Tray to summon two tabs with more information about your connection. This is largely identical to the Local Area Connection Status window.

General: Displays information about your connectionif you're connected, how long you've been connected, how fast the connection is, and how strong the wireless signal is. The new addition is the View Wireless Networks button; click it to open the Wireless Network Connection window.
Support: This tab displays troubleshooting information about your connectionIP address, gateway, and so on. The Repair button resets your connection if anything goes wrong, although Windows will attempt to reconnect on its own. You're not likely to solve a lot of problems here, but it's a good place to start if your connection is misbehaving. Your best bet when troubleshooting a wireless connection is to choose the General tab and click the Properties button to change the settings of the wireless connection.

To bring up the Wireless Connection Properties window, click the Wireless icon in the System Tray to bring up the Status window, then click the Properties button, where you can access the settings that are shown in the following list.

Use Windows to configure my wireless network settings: Some wireless hardware comes with its own software to handle connection duties , and Windows will stay out of the way. Checking this box puts Windows back in control. This is usually a good idea.
View Wireless Networks: Click the View Wireless Networks button in the Available Networks area to list every network that Windows can see.
Preferred Networks: Windows keeps a record of the networks that you've connected to (which it assumes are ones you prefer), making it easy to automatically connect to them again when you come within range. This is especially useful for laptop users. XP runs down this list in order until it finds a network it can access, automatically sending the WEP key if necessary. You can change the order of networks in the list by using the Move up and Move down buttons .
Advanced: This button opens a small dialog box that controls which kinds of networks Windows will try to access. By default, Windows will go for anything on your Preferred Network list. Infrastructure mode restricts you to access points (the most common method of connecting to a wireless network), while the ad hoc mode lets you form computer-to-computer connections. Check the "Automatically connect to non-preferred networks" box and Windows will try to connect to a network you haven't directly configured. For security reasons, this box should be unchecked unless you have a specific reason to use this featuresay, you need to connect to lots of networks when you're on the move.

To edit an individual connection, select it from the Preferred networks list and click the Properties button. The three tabs on this dialog box control the connection's security (see Figure 7-9).

Figure 7-9. From the Wireless Networks tab (left), you can view available nearby wireless networks. Select a network and click the Properties button and you can control its security features (right).

Association: On unsecured connections, this tab's contents are almost entirely grayed out. If there is no security key and Data encryption is set to Disabled, Network Authentication is set to Open. If not, the Network Key box will let you type in a key. The only exception: if the key is built into the wireless network adapter, check the "The key is provided for me automatically" box.
Authentication: Grayed out unless WEP has been selected on the Association screen, this is where you switch on 802.11x security and tell Windows about your EAP (Extensible Authentication Protocol) typeeither validated by a third-party server, or via a smart card. Depending on which you select, the Properties button will display slightly different optionsincluding which Trusted Root Certification Authorities to consult , and whether you should log in using your Windows name, domain and password. You can also choose whether to log in as a guest when your computer information is unavailable.
Connection: A straightforward optionshould Windows automatically make this connection? One easy checkbox.

7.1.2.3.3 Other connection actions

In addition to Properties, there are other items available on the connection icons' context menus (depending on the connection type):

Enable/Disable

This allows you to selectively enable or disable permanent connections, such as LAN or High-Speed Internet connections. Disabling a connection is effectively the same as pulling out the cable; a red X will appear over the icon of a disabled connection.

Connect/Disconnect

Connect establishes a temporary connection, and Disconnect breaks that connection. For Dial-up connections, these commands dial and hang up, respectively. For Broadband connections, these commands login and logout, respectively.

If the "Show icon in notification area when connected" option is enabled in the connection's properties window, you can also access Disconnect by right-clicking the connection icon that appears in the Taskbar tray. You can also open the connection's Status window (see Figure 7-10) and click Disconnect.

Status

This is the default action for all connections; double-click any connection to view its Status window (see Figure 7-10). The Status window shows the amount of time the connection has been active, the number of TCP packets sent and received, and even the IP address of the connection (in the Support tab). Also available are buttons for the other actions where applicable , such as Enable/Disable, Connect/Disconnect, Properties, and Repair.

Figure 7-10. The Status window displays information about the current network connection

If you suspect that a connection is down, check the packets sent and received in the Activity section of the Status window; if the numbers change when you, say, try to open a web page or check your email, the connection is still active.

Repair

Repair reinstalls the drivers associated with the connection. If a connection does not appear to be working, try disabling it and then reenabling it (or disconnecting and then reconnecting, if applicable). If that doesn't work, then try Repair.

Set as Default Connection/Cancel as Default Connection

Available only for temporary connections, such as Dial-up connections and Broadband connections. If a connection is set as the default connection, and Windows is configured to dial automatically (through Control Panel [Network and Internet Connections] Internet Options), it will be connected automatically when needed. If you have more than one connection of this type, use Set as Default Connection to determine which one gets connected automatically.

A black checkmark in a circle will appear over the connection icon for any connection that is set as the default.

Bridge Connections

Simply put, this allows data to be transferred between two (or more) different networks. In effect, a bridge turns you computer into a hub of sorts, but with the advantage of allowing you to combine two otherwise incompatible networks. Windows XP supports only one bridge at any given time, but a single bridge can contain as many different connections as you want.

Select at least two connection icons, right-click, and select Bridge Connections (or go to Advanced Bridge Connections) to create a network bridge between the connections.

Create Copy

Any network connection that can be added with the New Connection Wizard can be copied . Create a copy of a Dial-up connection, for example, to have two connection profiles without having to enter all the information twice. Create Copy is also handy for creating a backup of a connection so that you can experiment with different settings without loosing a working profile.

Note that if you want to add only alternate phone numbers, you can right-click the connection, select Properties, and click Alternates.

7.1.3. Protocols and Services

When you view the Properties window for a connection (see Figure 7-6, earlier in this chapter), you'll see the "This connection uses the following items" list (either in the General tab or the Networking tab, depending on the connection type). This list, also accessible via Network Connections Advanced Advanced Settings, shows all of the installed protocols and services. You can selectively choose which protocols and services are supported by any specific connection with the checkboxes in the list.

If you need to add support for a protocol or service not shown in the list, click Install to add it. If a protocol or service is shown but you're certain it's not used by any of your connections, you can uninstall it. If you install or uninstall a protocol or service, the change will take effect for all existing connections.

Probably the most useful button, however, is Properties. Depending on the service or protocol currently selected, Properties allows you to set many of the advanced options for a connection. The following list shows common services and protocols available in Windows XP:

Client for Microsoft Networks

An essential component for connecting to a Microsoft Network. This entry should always be present and enabled, unless you specifically need to connect to a non-Microsoft network (such as NetWare). This entry has one setting in its Properties window, and most users will have no need to modify it.

File and Printer Sharing for Microsoft Windows

The service responsible for sharing files and printers over a Microsoft Network; see Section 7.2.2, later in this chapter, for more information. This component should be enabled for LAN connections, and disabled for Internet connections. The Properties window is unavailable for this entry.

Internet Protocol (TCP/IP)

The TCP/IP protocol, introduced in the beginning of this chapter, is the protocol used by all Internet connections, as well as most LAN connections. Unless you specifically don't want TCP/IP support for some reason, the Internet Protocol (TCP/IP) entry should be enabled for all of your connections.

Select Internet Protocol (TCP/IP) and click Properties to view and change the connection's TCP/IP settings. The Internet Protocol (TCP/IP) Properties window, shown in Figure 7-11, is where you set the IP address of your connection (if you have a static IP address), as well as the subnet mask, gateway, and DNS server addresses. If the connection has a dynamic IP address (assigned randomly every time you connect), choose the "Obtain and IP address automatically" option.

Figure 7-11. The Internet Protocol Properties Window

Click Advanced to configure multiple IP addresses and multiple gateways, use more than two DNS servers, set up WINS, and enable NetBIOS over TCP/IP. Choose the Options tab to configure TCP/IP filtering, which allows you to selectively permit or deny communication based on the port (described at the beginning of this chapter). Note that this is somewhat like a firewall, described in "Implementing Network Security," later in this chapter.

NWLink IPX/SPX/NetBIOS Compatible Transport Protocol: Enable this entry to add support for the IPX/SPX (Internetwork Packet eXchange/Sequenced Packet eXchange) protocol. IPX/SPX is used by Novell NetWare networks, as well as some old DOS games and some network printers. Unless you know specifically that you need IPX/SPX support, you probably don't need this protocol.
NWLink NetBIOS: Use this protocol to connect to a NetWare server running Novell NetBIOS. If you use only Microsoft-compatible networks, you'll have no use for this protocol. This entry has no properties.