Home and Small Office Local Connections | Microsoft Windows XP Professional Resource Kit 2003

A local area connection is automatically created for each network adapter in your computer that is detected by Plug and Play. After a network adapter is installed, it is detected by the Plug and Play service. Network Connections enumerates the adapter and populates the Network Connections folder with a local area connection. Because local area connections are dependent upon a network card being recognized in the computer, they cannot be created by using Create a new connection.

For the adapter to be detected and the connection created, Plug and Play, Network Connections, and Remote Procedure Call (RPC) services must be started. All of these services start automatically; no user interaction is required.

A local area connection might not appear in the Network Connections for any of the following reasons:

The network adapter was removed. A local area connection only appears if an adapter is detected.
The installed network adapter is malfunctioning.
If your network adapter is a legacy adapter that is not detected by the Add Hardware Wizard or Plug and Play, then you might need to use the Add Hardware Wizard to set up the adapter manually in Device Manager before you see a local area connection in the Network Connections folder.
If the network adapter driver is not recognized, the adapter appears in Device Manager but you cannot see a local area connection. If your network adapter driver needs to be updated, use the Update Driver feature in the adapter s property sheet.

If your computer has one network adapter, but you need to connect to multiple LANs (for example, you use Dynamic Host Configuration Protocol (DHCP) at work but a static IP address configuration at home), you can configure TCP/IP with an alternate configuration. With an alternate configuration, your computer first tries to locate a DHCP server, and then if one is not found, it configures TCP/IP with the static configuration. For further information on alternate address configuration, see Configuring IP Addressing and Name Resolution in this book.

Note

Windows XP Professional peer-to-peer networking can comfortably handle as many as 10 computers. (Microsoft added a software limitation to Windows XP Professional to prevent you from peer-to-peer networking more than 10 computers. Beyond 10 computers, you will want to configure a Windows 2000 Server based computer as a domain controller.)

Use the network adapters that are supported by Windows XP Professional and listed in the Hardware Compatibility List link on the Web Resources page at http://www.microsoft.com/windows/reskits/webresources

Clients, Services, and Protocols

By default, the following clients, services, and protocols are installed with a local area connection:

Clients. Client for Microsoft Networks (allows you to access file and print shares of other Windows based computers).
Services. File and Print Sharing for Microsoft Networks (allows you to share your own computer resources) and QoS Packet Scheduler (enforces QoS parameters for a particular data flow).
Protocols. TCP/IP, with automatic addressing enabled.

Any other clients, services, and protocols, including Internetwork Packet Exchange/Sequenced Packet Exchange (IPX/SPX), must be installed separately.

For information about configuring TCP/IP for a local area connection, see Configuring TCP/IP in this book.

Local Area Connection Status

Like other connections, the appearance of the local area connection icon changes according to the status of the connection. The icon appears in the Network Connections folder, or if the network cable is disconnected, an additional icon appears on the taskbar. If a network adapter is not detected by your computer, a local area connection icon does not appear in the Network Connections folder. Table 23-4 describes the different local area connection icons.

Table 23-4: Local Area Connection Icons
Icon	Description	Location
	The local area connection is active.	Network Connections folder
	The cable is unplugged from your computer, or from the wall or hub.	Network Connections folder
	The cable is unplugged from your computer, or from the wall or hub.	Taskbar
	The driver is disabled.	Network Connections folder
None	The network adapter was not detected.	No icon appears in the Network Connections folder

To view the status of a local area connection

Right-click the local area connection, and then click Status.

The General tab in the Local Area Connection Status dialog box, which is visible by default, provides information about the connection including its status, its duration, its speed, and the number of packets sent and received.
The Support tab on the Local Area Connection Status dialog box displays data including address type, IP address, subnet mask, and default gateway. Clicking the Details button displays a summary of advanced network data, including the network adapter s physical (or MAC) address and the IP addresses of DHCP, DNS, and WINS servers. The Support tab is the equivalent to the Winipcfg.exe tool provided with Windows Me, Windows 98, and Windows 95.
To automatically enable the Status monitor each time the connection is active, right-click the local area connection, click Properties, and then select the Show icon in taskbar when connected check box. By default, the Status monitor is disabled for local area connections, but enabled for all other types of connections.

WAN Adapters

Permanent connection WAN adapters such as T1, Frame Relay, and ATM, also appear in the Network Connections folder as local area connections. For these adapters, some settings are autodetected, and some need to be configured. For example, for a Frame Relay adapter, the appropriate management protocol, Committed Information Rates (CIR), Data Link Connection Identifiers (DLCIs), and line signaling must be configured. For these settings, contact your Frame Relay service provider. Default settings might vary according to the adapter.

The Network Bridge

The Network Bridge provides an IEEE 802.1D transparent bridge for grouping network interfaces at the media access control (MAC) sublayer of the OSI data-link layer. The bridge implements the spanning tree algorithm for prevention of bridged loops in the LAN segment topology.

A bridge in Windows XP Professional simplifies the setup and administration of a subnetted home network. The classic model of a subnetted IP network involves:

Assigning each network segment a subnet identifier (ID).
Correctly assigning IP addresses and subnet masks and configuring packet forwarding on the computers connecting the subnets.
Configuring name resolution servers.

Bridging the LAN segments that comprise a home network simplifies the situation by creating a single subnet. The entire home network can then operate with a single subnet. DHCP client computers on any LAN segment in the home network automatically obtain an IP address, subnet mask, and default gateway from the host computer on which ICS is enabled.

Note

Bridging is a MAC layer activity, making use of a single subnet ID. ICS is a network layer activity, employing a single public IP address. The two are not related. However, the Network Bridge only works with TCP/IP.