Networking with Windows

Connecting a Network The pattern of hardware and software connections that ties workstations to a network is referred to as the network topology. After completing this lesson, you should be able to: Distinguish among Ethernet, FDDI, and token ring topologies Recognize different types of network addresses List available addressing protocols Identify other protocols used on a network

Network Topologies Imagine an aerial view of a network. Picture the network's general shape. The pattern of connections that ties the workstations to the network is its topology. Let's take a look at the topologies you'll encounter on the A+ exams.

Ethernet: Sometimes referred to as bus topology, Ethernet uses a full range of network media (using copper or fiber optics) and operates at 10 Mbps, 100 Mbps, or 1000 Mbps (1 Gbps). The 100-Mbps Ethernet is called Fast Ethernet and 1000 Mbps Ethernet is called Gigabit Ethernet. An Ethernet network (LAN) can support about 500 nodes. This is the most commonly installed type of network, probably because it is the cheapest and simplest. Ethernet devices connect to either a hub or a switch that is in turn connected to the network backbone.

Token Ring: Sometimes referred to as ring topology, Token Ring also uses copper and fiber-optic cabling, operates at 4 Mbps to 16 Mbps, and supports about 260 nodes. A Token Ring network operates reliably but can be difficult to troubleshoot. Because IBM is involved with the exams now, look for at least one Token Ring question.

FDDI: (Sometimes pronounced as fiddy, but it's usually just spelled out.) FDDI stands for Fiber Distributed Data Interface. An FDDI NIC contains a laser or diode transceiver that converts its digital data into light to be transmitted on a fiber-optic network or back to a digital signal from incoming light impulses for use by the PC. FDDI is a standard of ANSI and the International Standards Organization (ISO) for data networks that use Token Ring topology with dual and redundant rings and data speeds of 100 Mbps.

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Connecting a Workstation to the Network Each network topology is associated with a network technology or protocol. Ethernet networking is the most common on a bus topology, and Token Ring is the most common on a ring structure. The network technology in use is important because when you connect a PC to the network for the first time, you need to know the network identity requirements for a new workstation.

Addressing the Network The three addressing elements that are used on a network are as follows:

MAC (Media Access Control) address: Every NIC or network adapter is assigned a unique ID called the MAC address by its burned into the NIC's firmware and cannot network addressing, and all other address is a 48-bit address that is expressed as 12 bits).

manufacturer when it is made. This address is be changed. The MAC address is the basis for all types are cross-referenced to it. A MAC address hexadecimal digits (a hex digit is comprised of 4

To display the MAC address (adapter address) of the NIC or NICs installed in a PC, you can use the WINIPCFG command on Windows 9x and Me systems or the IPCONFIG /all command on Windows 98, Me, NT, 2000, and XP systems. The results of IPCONFIG /all on a Windows XP computer are shown here and on subsequent pages.

IP (Internet Protocol) address: Many internal and all external networks use IP addresses to identify nodes on both LANs and WANs. An IP address for a network workstation combines the address of the network and the node into a 32-bit address that is expressed in four 8-bit octets (which means sets of eight).

Networking with Windows

3 The IPCONFIG command displays the IP addressing information for a workstation on Windows 98 and all later versions. As shown here, the IPCONFIG command displays the IP address that is assigned to the workstation (in this case, 192.168.3.167), the workstation's subnet mask (which is used to differentiate between the network and host portion of an IP address), and the default gateway of the node. To run this command, open a command prompt and enter IPCONFIG on the command line.

Network names: The most common type of network name is computer names, which are also called network names. A network name is the name assigned to a workstation or other networked device and used to identify that node by other network users. For example, it is much easier to find a printer with a network name or MAIN_LASER than trying to remember the printer's MAC or IP address.

Commonly, network names are NetBIOS (Network Basis Input/Output names. NetBIOS uses unique 15-character names that are periodically broadcast network so the names can be cataloged by the Network Neighborhood function. names are the names that show up in Windows Network Neighborhood. In the shown here, the NetBIOS name of the computer is XPPRO1.

System) over the NetBIOS example

DHCP (Dynamic Host Configuration Protocol): This protocol is used to automatically configure a network workstation with its IP address data. Each time that the workstation is logged on to the network, the DHCP server software, running on a network server or router, assigns or renews the IP configuration of the workstation. Typically, the MAC address is used to uniquely identify the workstation, and the IP address is assigned from blocks of IP addresses that have been set aside for use by internal networks. Depending on the network operating system, the IPCONFIG or WINIPCFG command can be used to view, renew, or release DHCP data.

Networking with Windows

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DNS (Domain Name System): DNS is used to resolve (translate) Internet names to their IP address equivalents. For example, when you request www.MyFavoriteBlog.com from your browser's location line, a nearby DNS server (typically at your ISP) converts it to an IP address, such as 12.168.1.100, which is then used to request the data across the Internet.

WINS (Windows Internet Naming Service): WINS is Microsoft's network name resolution software that converts NetBIOS names to IP addresses. Windows machines are assigned NetBIOS names, which are converted into IP addresses for use on a network using TCP/IP (Transmission Control Protocol/Internet Protocol), the foundation protocol suite of the Internet. The use of a WINS server allows nodes on one LAN segment to find nodes on other LAN segments by name.

Connecting to an Ethernet Network When a new workstation is added to an Ethernet network, the workstation identifies itself using its MAC address and computer name to the rest of the network. The workstation is also assigned an IP address (either by DHCP or some other means). Devices on the network that need to hold this addressing information, such as a switch or bridge, store the information in their MAC address tables. When requests come in for a particular IP address, the MAC address of the node is looked up and the message is sent to that workstation. This description is highly simplified, but it represents the essence of what happens.

Connecting to a Token Ring Network When you add a new node to a Token Ring network, the node must first establish that its address is unique. The workstation sends out test frames with its ID address, and the system responds with its own test frames that are sent to that address. If no other node responds, the new ID address is accepted and established for the new ring node. If duplication exists (it can happen), jumpers or DIP switches on the NIC can be used to alter the address.

Networking with Windows

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On a token-ring network, the ID is the same as the MAC address.

Protocols and Other Niceties In addition to the three network protocols (Ethernet, Token Ring, and FDDI) described earlier, other protocols can be used to interconnect PCs to other PCs or networks. For the test, you need to know the names of these protocols, their acronyms, and the scope of what they interconnect.

Networking and Communications Protocols Protocol/Layer

Acronym What It Does

Point-to-Point Protocol

PPP

Used to connect and manage network communications over a modem

Transmission Control Protocol/Internet Protocol

TCP/IP

The backbone protocol of the Internet

Internetwork Packet

IPX/SPX

The standard protocol of the Exchange/Sequenced Novell network operating system's Packet Exchange

NetBIOS Extended User Interface

NetBEUI

A Microsoft protocol that is used only by Windows systems for LANs with no external connections; does not support routing (addressing through a router to other networks)

File Transfer Protocol

FTP

Used to send and receive files in client/server mode to or from a remote host

Hypertext Transfer Protocol

HTTP

Used to send World Wide Web (WWW) documents, which are usually encoded in HTML across a network

Network File Services NFS

Allows the network node to access network drives as if they were local drives, files, and data; also performs the file-access and data-retrieval tasks that are requested of the network

Simple Mail Transfer Protocol

SMTP

Used to send electronic mail (e-mail) across a network

Telnet

Telnet

Used to connect and log in and manage a remote host

Networking with Windows