Windows.XP.in.a.Nutshell.1002005.2Ed [Electronic resources] نسخه متنی

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 "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.

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.

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.