Networking_p_2013-02-04_.pdf

APTECH COMPUTER EDUCATION

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What is a Computer Network? A computer network is a collection of hardware and software that enables a group of

computers to communicate with each other, and to let network users share resources. Each computer on the network is sometimes called a node.

Shared resources can be data, like files, folders, or mail messages; software applications; or hardware, like printers or modems. Most organizations use networks because networks make it easy to share these valuable resources. Computer networks are everywhere from a simple, two-PC home setup to the vast resources of the Internet. But any computer network includes certain basic components, whether youre running a Windows operating system or some other kind of software.

Common Network Components The following table lists some of the common hardware and software components in any computer network. Component Definition Any computer that makes resources available to other computers on the

network. Server computers run network server software. Client Any computer that uses the resources of a server. Client computers run

network client software. Media The physical means of communication between network computers. In the

figure, the network medium is a specialized cable. Other media include infrared transmission, radio signals, and telecommunications lines.

Resources The data, applications, and hardware provided by network servers for use by network clients. In the figure, the printer is a shared resource.

Network adapter A special adapter card that enables two computers to send data out over the network media. Sometimes a modem can function as a network adapter, if youre using phone media to connect your network.

Network protocol A specialized electronic language that enables network computers to communicate.

Network topology The physical layout of a network. This often includes specifications for the types of media, adapters, and protocols the network can use.


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Types of Networks:

Networks can be categorized in many different ways; by their scope, their architecture, or by what type of operating system they use. Lets look at some of the ways you can describe the different categories of networks.

Network Scope One way to categorize a network is by the scope of the network coverage. There are two major divisions in network scope:

Figure: Network scope. 1. A Local Area Network (LAN) consists of any number of computers that are linked

directly together and are housed in a clearly-defined geographic area, such as in a single building. A LAN can only be as large as the physical limitations of the cabling you use, which varies depending upon the cabling type.

2. A Wide Area Network (WAN) can span large geographic areas like countries and continents. In a WAN, at least some of the connections rely on long distance communications media such as satellite links, long-distance fiber optic cable, or specialized high-speed telephone lines. These media are expensive; companies normally share the links or lease capacity from a public carrier such as a telecommunications company. But WAN technologies are essential to link all the computers in a multi-site or multi-national enterprise in a reliable way. WANs can be enormous; the Internet is the ultimate WAN.

[Note that the key characteristic of a LAN or a WAN is not how big it is but the technologies used to connect the computers together. There are other, more specialized types of networks. Here are some of the ones you might encounter:]

3. A Metropolitan Area Network (MAN) is a sort of mini-WAN thats typically confined to a single municipality. A company might use a private MAN to link several different office buildings together within the same city.

a. A Storage Area Network (SAN) is a specialized LAN that links together several network servers that are dedicated to storing large amounts of data in a


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centralized, secure repository. The servers in the SAN manage large banks of hard disks or tape drives and are connected to each other by extremely fast, reliable, high-speed media. SANs are useful to firms that need extremely large data storage capacity, high reliability, and fast retrieval.

b. A Value-Added Network (VAN) is a public network utility that provides both network access and additional proprietary services to its users. For example, America on Line (AOL) is a VAN. It provides its subscribers with standard network services such as Internet access and email, and also offers additional features such as private AOL chat rooms, message boards, and news summaries.

Network Operating Systems Another way to describe or categorize a network is by the kind of NOS that runs the network. There are several different operating systems that todays PC-based networks are built on:

1. Microsofts Windows 2000 and its predecessor, Windows NT, Windows Server 2003, Windows Server 2008

2. Novells NetWare. 3. The UNIX family of operating systems, including LINUX.

For smaller networks: 1. Apple Computers Macintosh operating system, using the AppleTalk network protocol. 2. Microsofts Windows 98, Windows XP, Windows 7, Windows 8.

In addition to providing basic network services, some network servers can serve specialized functions, too. Some of these dedicated functions include:

1. A print server, which is dedicated to managing printers and network printing jobs. 2. Communications servers, which manage access to modems or other types of

communication links. 3. Database servers, which store large databases and run database applications. 4. Applications servers, a generalized term for any server that runs an application for access

across a network. 5. Mail servers, which provide access to email services and store and forward email

messages. 6. Internet or Web servers, which provide a wide variety of information to the public

Internet or to private intranets.


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Network Models The final major way to categorize a network is by the networking model it uses. The networking model refers to the degree of centralized control thats built into the network. Most networks can be categorized as one of two types:

Peer-to-peer Networks In this kind of network, any computer can act as both a server and a client. Any computer

can share resources with another, and any computer can use the resources of another, given proper access rights. Creating a peer-to-peer network, say by linking together two or three computers in your home office, can be a simple and relatively inexpensive way to add storage space, share information, and share access to expensive peripherals such as a CD-ROM drive tower or a color laser printer. You dont need a centralized server, and you dont need a centralized administrative staff, though you will need to have some networking knowledge and expertise in order to maintain and troubleshoot the network.

Figure: A peer-to-peer network.

Peer-to-peer networks have a few limitations: 1. For practical reasons, they cant be very big. Generally, once you get beyond 10

computer users, administering a decentralized network becomes too complicated. 2. Its harder to optimize your computer hardware needs, because each computer needs to

be available to support the needs of the local user as well as users who connect to it across the network. With a more centralized network, you can concentrate the hardware resources where theyre needed; putting the biggest hard disk on the file server, for example.

3. Lots of different people are responsible for maintaining, controlling, and administering different parts of the network. You cant count on all these tasks being done in a consistent way; youll probably also need to provide each user with some additional training to give them the skills they need to manage their portion of the network.

4. Security isnt centralized, which makes the network harder to administer and less secure. Each shared resource on a network computer is linked to a user account that exists on that computer, or is protected by a single password. So, you must coordinate multiple,


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duplicate user accounts, or make sure passwords are set, maintained, and protected appropriately. Nonetheless, a simple peer-to-peer network can be a great solution for a small office, home office, or departmental workgroups networking needs.

Client-server Networks In this network model, at least one centralized server manages shared resources and

security and administers the other network users and computers. Generally, the network servers are not used as clients; they are dedicated to their network services and are usually physically secured by being locked in a server room to prevent casual access. With a client-server type network, youll need to invest some time, money, and training to create and maintain the central server and build a qualified administrative staff.

Figure: A client-server network.

Here are some of the advantages of client-server networks: 1. You can concentrate your resources on optimizing the computer that youre going to use

as a server so that it can meet the processing and storage needs of the network users. 2. You can support lots more users than in a peer-to-peer network. Client-server networks

can scale to support thousands or even millions of users. 3. This network model enables you to administer your resources centrally, using a

dedicated, specially-trained team. This provides more consistency and reliability. 4. Storing data centrally makes it easier to secure, monitor, and back up. 5. Centralizing security makes security more consistent and protects the network better.


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Combination Networks As the name implies, combination, or hybrid, networks combine both client server and peer-to-peer network elements. As a matter off act, most large networks today are likely to have some peer resource sharing existing alongside the centralized system.

Figure: A combination network.

[These networks can be very flexible, but are also potentially difficult to administer and monitor.]

Network Media Access Methods and Network Topologies

Media access is the method by which different stations on a network get their turn to put data on the network cable. A network topology is the underlying physical layout of the network.

Media Access Control Because only one computer can put data on the wire at a time, a Media Access Control

method is needed to make sure each computer gets appropriate access to the cable. Without proper media access you could have:

1. Collisions and destroyed data. 2. Under-utilization of the network medium. 3. A few nodes monopolizing the network.

The four most common media-access methods are contention, polling, token passing and demand priority.

Contention In the contention method, each station is responsible for listening until the channel is free before transmitting. More than one station might attempt to transmit at one time, in which case a collision occurs. In that case, both stations wait for a brief period and then try again.


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Figure: Contention media access.

There are two different types of contention methods: Carrier Sense, Multiple Access/Collision Avoidance (CSMA/CA), and Carrier Sense, Multiple Access/ Collision Detection (CSMA/CD); they differ in how they handle the problem of collisions.

Method Description CSMA/CA Each computer sends a short test message out to detect collisions. If this message

doesnt collide with any other, the computer transmits the data. This increases network traffic because each data message is preceded by the test message.

CSMA/CD In this method, the computers just send the data on the wire, after checking to see if it is free. If theres a collision, they just resend their data.

An advantage to contention is that it makes good access of the network channel. It does have these disadvantages:

1. It doesnt guarantee any one station a turn at the network; it just makes it probable that each station will get a turn. One station can theoretically hog the channel.

2. In periods of heavy network traffic, there are more collisions; which means computers have to resend data, which increases the traffic again.

3. You cant prioritize devices to give some faster access.


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Network Topologies A network topology is a description of how the network is layout or arranged. There are two different aspects to the network topology. The physical topology describes the physical structure of the cable that connects the network computers. The logical topology describes the path that signals take as they flow through the network. The two dont have to match exactly. Physical topology is defined at the Physical layer; logical topology is defined at the Data Link layer. There are four primary types of network topologies, and lots of combinations and variations on these basic themes!

Bus Topology In a bus topology the cable is arranged in a long straight line, and each computer attaches to the cable directly or by using a short drop cable. A bus topology is passive; each computer is only responsible for traffic directly addressed to it. The nodes dont actively move each signal along, so any one computer can go down and it wont affect the whole network.

Figure: Bus topology.

The advantages of a bus topology are: Its easy to install. Just run the cable and plug in. It doesnt use much cable. Individual computers can fail without affecting the network.

Disadvantages are: A break in the cable brings down the whole network. Its hard to troubleshoot; a small problem can affect a lot of computers. Its hard to reconfigure. You have to keep devices spaced at a fixed interval. The ends of the bus must be properly capped or terminated or signals bounce back and

become unintelligible.

Ring Topology In a ring topology, the computers are arranged in a circle. Data moves around the ring in one direction. Its an active topology; each computer has to take responsibility for moving the data along.


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Figure: Ring topology. For fault-tolerance, some systems use a dual ring. One ring is the primary method, and the other is used as a backup. Data goes in one direction in the primary ring, and the opposite direction in the secondary ring. So if theres a failure, messages can back up and go around the block, so to speak, to avoid the problem area. Here are the advantages of a ring topology:

No loss in signal quality because each computer retransmits the signal. Easy to install. Easy to troubleshoot, because its easy to locate the fault areas. No need to terminate able.

And some disadvantages: Unless you have a dual ring, which is expensive, a single failed station can bring down

the whole network. Its hard to reconfigure large rings. It uses more cable than the bus topology. As with all networks, there are limitations in the size of the ring and the number of

devices.

Star Topology In the star topology, the computers are connected to a central device called a hub. The cables go out from the hub in all directions. Most hubs are active, and regenerate each signal. Other hubs are passive, and act only as connection points. The computers in the topology are all passive.

Figure: Star topology.

Now, heres a good example of where the apparent physical topology doesnt have to match the actual logical topology. Some networks look like stars because theyre connected to a hub. But


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inside the hub the connections go from one to another in a straight line, like a bus. Its really a bus topology, but thats not visible from outside the hub. The advantages of a star topology are:

Its quite inexpensive. Its easy to troubleshoot. If theres a media failure, it only affects one computer. Its easy to reconfigure. Just plug and unplug your devices.

Disadvantages are: Data transmission rates are low. There arent any de jure standards. It requires a lot of cable. Its somewhat difficult to install; you have to find paths to run all that cable to the hub.

Mesh Topology In a mesh topology, every node is connected to every other node. Heres a picture of a simple mesh topology; imagine how this would look with two hundred nodes!

Figure: Mesh topology.

The main advantage of a mesh topology: great reliability. And the main disadvantage: lots and lots of cable and connections. Mesh topologies arent very common in practice.

Hybrid Topologies In reality, network topologies might combine characteristics from more than one of these standard patterns. This is usually because a functioning network is really a combination of several smaller networks. Networks that combine more than one topology are called hybrid networks.


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Figure: Hybrid topology.

There are two particularly common types of hybrid topologies: The star bus combines several star networks. The hubs of each of the stars are linked

together via a bus. The star ring is similar, but the hubs are connected in a ring.

Hybrid topologies are almost inevitable; but the more diversity you have in your network, the more complex it will be to maintain and troubleshoot.

Physical Network Components To connect your network together, you need some physical connection between your computers. There are three main types of physical components youll need to install and maintain in your network: cables, connectors, and adapters.

Types of Network Media Network transmission media can be characterized in various ways. Here are a few of the key terms youll hear people use to describe the characteristics of transmission media:

Bounded media transmit signals by sending electricity or light over a cable or wire. Twisted-pair, coaxial, and fiber-optic cable, which are all bounded media.

Unbounded media transmit data through the open air. Radio waves, laser or infrared signals, and earth- and satellite-based microwaves are all unbounded media. Some of these, like infrared, require short line-of-sight connections. Others, like satellite microwave, can span huge distances without the use of enormous cable runs.


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Figure: Unbounded media.

You can also describe the particular media type in terms of several key data transmission characteristics:

Attenuation is the weakening of a signal over distance. Many types of media are subject to some degree of attenuation.

The amount of data that can be carried on any transmission medium is the bandwidth. Youll see bandwidth measured in cycles per second (Hertz, or Hz) or in bits per second (bps). Generally, the more bandwidth, the more data can be transmitted.

The data rate is the speed at which the data actually moves through the cable. Its also measured in bps. A way to keep bandwidth and data rate straight is to think of the bandwidth as the number of lanes on a highway, and the data rate as the speed limit.

Bandwidth and data rate combine to produce throughput. This is the actual amount of data that gets from point A to point B in a given time. To use our highway analogy, a one-lane highway with a 65 MPH speed limit and a 3-lane highway with a 45 MPH speed limit might actually be able to move the same number of cars at rush hour.

Figure: Bandwidth vs. data rate.


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Networks can use one of two basic types of transmission mechanism: Some media are designed for baseband transmissions. Baseband transmissions can carry

a single digital signal (a series of on/off electrical pulses) at a time, in one direction only. Stations have to take turns transmitting.

Another transmission method is broadband. Broadband uses analog signals (waves); the analog signals can be divided up into different frequencies to carry multiple messages at the same time. Broadband media can transmit in only one direction; you need two cables, one for upstream and one for downstream communication, for two-way communication.

Figure: Baseband vs. broadband. Twisted-Pair Cable and Connectors Twisted-pair cable is one of the most popular transmission media in use in LANs today. It consists of a pair of cables twisted around each other inside a protective sheath. There are two main types, which you can see in the following illustration: unshielded twisted pair (UTP) and shielded twisted-pair (STP), in which the wires are also encased in an inner sheath of wire mesh.

Figure: UTP and STP cables.

The twisting in the cable protects against electromagnetic interference (EMI), which happens when extraneous signals, either from outside sources like a power supply or from adjacent wires,


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leak onto the cable or interfere with communication. When EMI is caused by signals from another cable, it creates crosstalk. Because of the shielding, STP is a lot less susceptible to EMI than is UTP. But its also more expensive! Networking is all about trade-offs like that. Advantages of twisted-pair are:

Its inexpensive Its easy to installyou just plug it in. It has well-established products and technology.

Disadvantages are: Its susceptible to EMI and to eavesdropping. (STP is safer than UTP.) It has low bandwidth. (STP is faster than UTP.)

Types of TP Cable There are lots of different types of twisted-pair cable. Each different type has different numbers of pairs of cables, different numbers of twists per wire, and so on. Even standard phone cable is a type of twisted-pair, but its not suitable for network communications. There are two different sets of standards that define TP cable types. First is the EIA/TIA 568 Commercial Building Wiring Standard:

Category Description Category 1 Traditional UTP telephone cable. Can transmit voice but not data. The

primary type of phone cable prior to 1983. Category 2 UTP cable with four pairs of wires. Certified to transmit data at up to 4

megabits per second (Mbps). Category 3 UTP cable with four pairs of wires, each twisted three times per foot.

Certified to transmit data at up to 10 Mbps. Category 4 UTP cable with four pairs of wires, certified to transmit data at up to 16

Mbps. Category 5 UTP cable with four pairs of wires, certified to transmit data at up to

100 Mbps. Category 5e UTP cable with four pairs of wires, certified to transmit data at up to 1

Gbps. Category 6 UTP cable with four pairs of wires, certified to transmit data at up to

10Gbps.

Twisted-Pair Connectors Twisted pair cable usually uses an RJ-45 connector. See figure below for a picture. This looks a lot like a standard RJ-11 phone connector, but its bigger and has eight connections instead off our.


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Figure: RJ-45 connectors. On a small twisted pair network, each computer might plug into a port on a device called a hub that provides a connection point to the network. Then, several hubs can be connected together. Or, each computer might plug in to a wall plate that looks something like a telephone jack. Wires run behind the wall plates to a centralized distribution area, containing a rack with shelves holding expandable patch panels.

Coaxial Cable and Connectors Another popular cable type is coaxial cable, or coax, so called because its made of a single-wire inner conductor surrounded by a layer of insulation, a wire mesh shield, and another layer of insulation. All the layers share the same axistheyre co-axial. The wire shield protects against EMI; the inner insulator protects the cable against shorting out on contact with the wire shield; the outer insulator protects the whole cable. Coax comes in two basic types: thick (thicknet) and thin (thinnet). Heres a picture of the two types:

Figure: Thicknet vs. thinnet.


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And heres a little comparison of their characteristics:

Thinnet Thicknet Can carry a signal up to approximately 185 meters (607 feet).

Can carry a signal approximately 500 meters (1,640 feet).

About a quarter of an inch thick. About half an inch thick Flexible and easy to work with; good for connecting individual computers.

Stiffer; used mainly as a backbone to connect several thinnet runs.

Here are some of the advantages of coax: Generally light, flexible, and easy to work with (thicknet is less flexible). Less susceptible to EMI than TP. Relatively inexpensive, although more expensive than TP. Well-established technology and product standards. More resistant to attenuation than TP, and so better suited to long distances.

And some disadvantages: More difficult and expensive to install than twisted pair because you have to run

individual wires and connectors; you cant just use patch panels. Still fairly susceptible to EMI.

Categories of Coax There are a variety of specifications for coax cable. These specs were originally developed for the military, and use abbreviated military terms. For example, RG means Radio Grade. The military uses a different categorization scheme now, but these names have stayed with the various cable types.

Coax cable type Description RG-58/U Solid copper core thinnet. RG-58 A/U Stranded copper core thinnet RG-58 C/U A military version of RG-58 A/U. RG-8 Stranded core thicknet RG-11 Dual-shielded, solid-core thicknet RG-59 Dual-shielded, solid-core thicknet used for broadband transmissions

like cable TV. Not suitable for networking. RG-6 Similar to RG-59, but thicker and can handle higher bandwidths. RG-62 Cable for the ARCnet networking specification.

Coax Connectors There are different types of connectors for thinnet and thicknet.

Thinnet uses various types of BNC connectors. There is some disagreement in the industry about what BNC stands for. Most people believe it means British Naval Connector, but other experts claim it stands for Bayonet Nut Connector, Bayonet Neill


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Concelman, or Bayonet Navy Connector. In any case, its what you use for thinnet. An important component on a thinnet network is the terminator, which is a special BNC device that goes on the end of the cable to prevent signals from bouncing infinitely on the wire. Heres a picture of some of the types for use in different situations.

Figure: Thinnet connectors.

Fiber-Optic Cable and Connectors The last media type well look at is fiber-optic cable. Fiber-optic cable transmits light signals through a strand of glass or plastic optical fiber, called the core. The core is encased in a tube of glass cladding. The cladding keeps the light stream focused inside the core. The cladding is surrounded by a tough outer jacket to protect it. The core can carry light only in one direction. Typically, a cable combines two separate jackets, for transmission in each direction.

Heres a picture of a fiber-optic cable:

Figure: Fiber-optic cable.

Fiber-optic cable uses either SMA connectors, which use a threaded nut, or ST connectors, which use a bayonet-style twist-to-lock system. Here are the advantages of fiber -optic cable:

Very secure, because its nearly impossible to tap. Isnt affected by EMI and doesnt produce EMI (it transmits light, not electricity). Very high capacity; in practical terms, 100 Mbps or higher.


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Lightweight. Very little attenuation; cables can be miles long. Low energy usage.

But, the disadvantages are: Its expensive. Its complicated to install. Its fragile. The product standards and technology arent as well-established, although this is

changing.

NETWORK DEVICES

The basic Network devices are: Individual Networks, Server, Hub, Switch, Bridges, Routers, Modems, Printers, DSL Modems & Routers, Gateways, Network Interface Cards, Cabling & Wireless Access Point.

1. NIC (Network Interface Card): Network Interface Cards are attached with the Computer or other Network devices and are used to provide the connectivity between the two Networks. Each Network card is specifically designed for the different types of the Network like Ethernet, FDDI (Fibre Distributed Data Interface), Token Ring and Wireless Networks. NIC basically defines the physical connection methods and the control signals that provide the timings of the data transfer over the Network.

2. Modems: Modems are the devices, which are used to translate the analog format into the digital data and vice versa. It performs the two main functions, Modulation and Demodulation. A modulated data can travel across the conventional telephone lines. The Modem modulates the signals at the sending end and demodulates at the receiving end. Modems are required for different types of the access methods such ISDN (Integrated Services Digital Network), DSL (Digital Subscriber Line) and 56K data modem. Modems can be the internal devices that plug into the Expansion Slots in a System or can be external devices that plug into the serial or USB ports. In Laptops, PCMCIA (Personal Network Memory Card International Association) cards are used for this purpose. In ISPs where the large scaled Modems are required, rack-mounted modems are used.


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3. Hub:- Hubs are used in Networks that use twisted-pair cabling to connect devices. Hubs can also be joined together to create larger Networks. Hubs are simple devices that direct data Packets to all devices connected to the Hub. Hubs come in a variety of shapes and sizes. Small Hubs with five or eight connection ports are commonly referred to as workgroup Hubs. Others can contain larger numbers of devices (Normally up to 32-64 connection port). These are referred to as high-density devices. Ports on a Hub are jacks (i.e., female connectors). In the case of a Hub for twisted pair cable, they are standard RJ-45 jacks.

4. Switch:- Switch is similar to Hubs. Like Hubs, Switches are the connectivity points of an Ethernet Network. Devices connect to Switches through twisted-pair cabling, one cable for each device. The difference between Hubs and Switches is in how the devices deal with the data that they receive. Whereas a Hub forwards the data it receives to all of the ports on the device, a Switch forwards it only to the port that connects to the destination device. It does this by learning the MAC (Media Access Control) address of the devices attached to it, and then by matching the destination MAC addresses in the data it receives.

5. Router: - Routers are used to create larger Networks by joining two Network segments. A Router can be a dedicated hardware device or a Network System with more than one Network interface and the appropriate routing Software. All modern Network Operating Systems include the functionality to act as a Router.

Routers can route data it receives from one Network onto another. When a Router receives a packet of data, it reads the header of the packet to determine the destination address. Once it has determined the address, it looks in its routing table to determine whether it knows how to reach the destination and, if it does, it forwards the packet to the next destination, or it might be another Router.

4. Bridge: - A Bridge is a device that connects and controls the flow of data between two LANs (Local Area Network)s or two segments of the same LAN. A device that connects two LAN segments together, which may be similar or dissimilar, such as Ethernet and Token Ring.


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A bridge is inserted in the Network to keep traffic contained within the segments to improve performance. By monitoring which station acknowledged (recognized) receipt of the address, bridges learn which nodes belong to the segment and maintain their own address tables. Multi-port bridges have more than two ports and perform a switching function just like a LAN switch.

5. Repeater: - A Repeater is a Network device that is used to regenerate or replicate signals that are weakened or distorted by transmission over long distances and through areas with high levels of EMI (Electromagnetic Interference).

Repeater is a hardware device that moves all Packets from one LAN segment to another. Repeaters boost (increase) a signals ability to travel farther on the Network. For example, 10Base2 coaxial has a maximum length of 185 meters, and 10/10BaseT twisted pair has a maximum length of 100 meters. Somewhere before the 185 and 100 meters are finished, it needs to provide a Repeater to extend the signal.

8. Gateway:- A Gateway is also called an IP Router. A Gateway can be a Device, System or Software. A device connected to multiple physical TCP/IP Networks capable of routing or delivering IP packets between them. A Gateway performs the function of translating the data from one format to another format without changing the data itself. A Network with two NIC cards can function as a Gateway. Router acts as a Gateway, e.g a router that routes the data from an IPX (Internet Packet eXchange) Network to an IP (Internet Protocol) Network is technically a Gateway. The same can be said of translational switch converts from an Ethernet Network to a Token Ring Network.

Protocol Sometimes referred to as an Access Method. A set of rules and conventions for sending Information over a Network. These rules administrate the content, format, timing, sequencing, and error control of messages exchanged among Network Devices. Each Protocol has its own method of how Data is formatted when sent and what to do with it once receives, how that Data is compressed and how to check for errors in Data. Protocol is the communication language or rule which establishes the Network within the Hosts (Nodes) on the Network. In Information Technology, a Protocol is the special set of rules that


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end points in a telecommunication connection use when they communicate. Protocols exist at several levels in a telecommunication connection. For example, there are Protocols for the data interchange at the hardware device level and Protocols for data interchange at the application program level. In the standard model known as OSI (Open Systems Interconnection), there are one or more Protocols at each layer in the telecommunication exchange that both ends of the exchange must recognize and observe. Protocols are often described in an industry or international standard. There are numerous types of Protocols some of them are listing below, which are mostly used:

TCP/IP (Transmission Control Protocol/Internet Protocol): TCP/IP was originally designed for the UNIX Operating System, and it is built into all of its family (i.e., Unix-like Operating Systems), including Linux and Mac OS X. Now a day it is compatible with most of all modern Operating Systems, and thus it enables almost any system to communicate with any other system as well as all types of Network hardware and Network configurations. TCP/IP is the suite (set, group) of communications Protocols that is used to connect Hosts on the Internet and on most other Network Computers as well. It is also referred to as the TCP/IP Protocol Suite and the Internet Protocol Suite. TCP/IP takes its name from its two main Protocols: TCP & IP. TCP operates at the Transport Layer. This layer is responsible for maintaining reliable end-to-end communications across the Network. IP is a Network Layer Protocol, which is the layer just below the transport layer. IP Protocol deals only with Packets (i.e., the most fundamental unit of TCP/IP data transmission), TCP enables two hosts to establish a connection and exchange streams of data. TCP guarantees delivery of data and also guarantees that packets will be delivered in the same order in which they were sent.

FTP (File Transfer Protocol): The Protocol commonly used to transfer files through a Network (Including the Internet). Basically, it is a way to copy files from one Network to another, commonly used in P2P (Peer-to-Peer) File Sharing.

POP3 (Post Office Protocol3): POP3 (Post Office Protocol 3) is the standard Protocol for receiving E-mail. POP3 is a Client/Server Protocol in which E-mail is received and held by Internet Server. This standard Protocol is built into most popular E-mail products, such as Eudora and Outlook Express. It is also built into the Microsoft, Netscape, and Yahoo & Googles Internet Explorer Browsers. Windows Server includes the POP3 service for providing clients with Mailboxes, and for handling incoming E-mail. POP3 is designed to delete mail on the Server as soon as the user has downloaded it. However, some implementations allow users or an administrator to specify that mail be saved for some period of time. POP can be thought of as a Store-&-Forward service.

IMAP (Internet Message Access Protocol): IMAP was developed at Stanford University in 1986. IMAP is a standard Protocol for accessing E-mail from local Server. IMAP (The latest version is IMAP Version 4) is a Client/Server Protocol in which E-mail is received and held


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by Internet Server. E-mail Client can view just the heading and the sender of the letter and then decide whether to download the mail. Multiple folders or mailboxes on the Server can be create and manipulate, delete messages, or search for certain parts or an entire node. IMAP also uses SMTP for retrieving E-Mail messages. It is similar to POP3 Protocol however, supports additional features not found in POP3. IMAP can be thought of as a RFS (Remote File Server). POP3 can be thought of as a Store-&-Forward service.

SMTP (Simple Mail Transmission Protocol): SMTP Protocol used in sending E-mail. It is usually used with one of two other Protocols, POP3 or IMAP that let the user save messages in a Server mailbox and download them periodically from the Server. In other words, users typically use a program that uses SMTP for sending E-mail and either POP3 or IMAP for receiving E-mail.

WAP (Wireless Access Protocol): WAP is a specification for a set of communication Protocols to standardize the way that wireless devices, such as cellular telephones and radio transceivers, can be used for Internet access, including E-mail, the WWW (World Wide Web), newsgroups, and instant messaging. While Internet access has been possible in the past, different manufacturers have used different technologies. The WAP was conceived (ideas) by four companies: Ericsson, Motorola, Nokia, and Unwired Planet (now Phone.com). The Wireless Markup Language (WML) is used to create pages that can be delivered using WAP.

DHCP (Dynamic Host Configuration Protocol): DHCP is a communication Protocol that lets Network Administrators centrally manage and automate the assignment of Internet Protocol addresses in an organizations Network. The DHCP Server assigns IP addresses from a predetermined (set) IP address range(s), called a Scope. A DHCP Scope can be defined as a set of IP addresses which the DHCP Server can allocate or assign to DHCP Clients. A Scope contains specific configuration information for Clients that have IP addresses which are within the particular Scope. Scope information for each DHCP Server is specific to that particular DHCP Server only, and is not shared between DHCP Servers. Scopes for DHCP Servers are configured by Administrators.


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IP Address: IP stands for Internet Protocol. A Routable Protocol in the TCP/IP (Transmission Control Protocol/Internet Protocol) suite that is responsible for IP Addressing, Routing, and the fragmentation and reassembly of IP Packets. The IP address is a numeric value of 32 bits in octate configuration separated by dots (Periods). There are 4 blocks. Each block contains 8 bit of numeric value. The range of IP address is defined by the IANA (Internet Assigned Network Authority) from 1.0.0.0 to 255.255.255.255. Among these range the IP address is classified in 5 classes A, B, C, D and E. Among these 5 classes of IP address, only the IP of class A, B, C are commonly used by public. The IP of class D and E are reserved IP address. Class D is reserved for multitasking and broadcasting purpose, class E is reserved for future use in scientific research.

For Internet Protocol Version-4 (IPv-4), a 32-Bit Address used to identify a Node on an IPv4 Internetwork. Each Node on the IP Internetwork must be assigned a unique IPv4 Address, which is made up of the Network ID, plus a unique Host ID. This Address is typically represented with the decimal value of each octet separated by a period (For example, 192.168.0.1). User can configure the IP Address statically or dynamically by using DHCP (Dynamic Host Configuration Protocol). Below is listing all IP Classes, Address Range & their supporting Host in details:

Class Address Range Supports

Class A 1.0.0.1 to 126.255.255.254 Supports 16 million Hosts on each of 127 Networks.

Class B 128.1.0.1 to 191.255.255.254 Supports 65,000 Hosts on each of 16,000 Networks.

Class C 192.0.1.1 to 223.255.254.254 Supports 254 Hosts on each of 2 million Networks.

Class D 224.0.0.0 to 239.255.255.255 Reserved for multicast groups.

Class E 240.0.0.0 to 254.255.255.254 Reserved.

All IP Addresses are broken down into 4 sets of octets that break down into Binary to represent the actual IP Address. The following chart is a basic example of the basic IP 255.255.255.255: IP: 255. 255. 255. 255.

Binary value: 11111111. 11111111. 11111111. 11111111.


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Octet value: 8 8 8 8

There are several IP Addresses used or automatically assigned on a Network. For example: 166.70.10.0 0 is automatically assigned Network Address.

166.70.10.1 1 is the commonly used Address used as the Gateway.

166.70.10.2 2 is also a commonly Address used for a Gateway.

166.70.10.255 255 is automatically assigned on most Networks as the Broadcast Address.

IP Address Assignment

1. Dynamic IP: - Dynamic IP is the changeable IP address which is automatically accepted by the hosts in two cases:

In case of configuring the DHCP Server when we use the client Server Network. In case of if we do not define the manual IP. If the NIC and its driver are installed and

proper configuration is done then in the properties of TCP/IP, the radio button Obtain an IP address automatically is selected.

2. Static IP: - This is the constant IP address. This IP address is defined manually by the user from the properties of TCP/IP.

Private IP: - Three blocks of IP addresses, A B & C are reserved for private use and are not routed over the Internet. Companies can assign these addresses to nodes on their private LANs at any time without conflict. This IP can be used free of cost by a normal user. The range of private IP in class A, B, and C are:

Class From To

Class A 10.0.0.1 10.255.255.254

Class B 172.16.0.1 172.16.255.254

Class C 192.168.0.1 192.168.255.254

Note: The range of class B 169.254.0.1 to 169.254.255.255 is reserved for MRIP (Microsoft Reserved Internet Protocol)/APIPA (Automatically Provided Internet Protocol Address).

Public IP: -This IP can be used only after paying the cost. This type of IP is used by the


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ISP (Internet Service Provider).

Subnet Mask

A Subnet Mask is a number that defines a range of IP addresses that can be used in a Network. Subnet Masks are used to designate (assign) Subnetworks, or Subnets, which are typically local Networks LANs that are connected to the Internet. Systems within the same Subnet can communicate directly with each other, while systems on different Subnets must communicate through a Router. Therefore, Subnetworks can be used to partition multiple Networks and limit the traffic between them.

Server Roles

The Windows Server 2003 family provides several server roles. To configure a server role, install the server role by using the Configure Your Server Wizard and manage your server roles by using Manage Your Server. After you finish installing a server role, Manage Your Server starts automatically.

To determine which server role is appropriate for you, review the following information about the server roles that are available with the Windows Server 2003 family.

The Windows Server can be configured with the following roles:-

a) File server role overview b) Print server role overview c) Application server role Overview d) Mail server role overview e) Terminal server role overview f) Remote access/VPN server role overview g) Domain controller role overview h) DNS server role overview i) DHCP server role overview j) Streaming media server role overview k) WINS server role overview

File server role overview

File servers provide and manage access to files. If you plan to use disk space on this computer to store, manage, and share information such as files and network-accessible applications, configure this computer as a file server.

After configuring the file server role, you can do the following:


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1. Use disk quotas on volumes formatted with the NTFS file system to monitor and limit the amount of disk space available to individual users. You can also specify whether to log an event when a user exceeds the specified disk space limit or when a user exceeds the specified disk space warning level (that is, the point at which a user is nearing his or her quota limit).

2. Use Indexing Service to quickly and securely search for information, either locally or on the network.

3. Search in files that are in different formats and languages, either through the Search command on the Start menu or through HTML pages that users view in a browser.

Print server role overview

Print servers provide and manage access to printers. If you plan to manage printers remotely, manage printers by using Windows Management Instrumentation (WMI), or print from a server or client computer to a print server by using a URL, configure this computer as a print server.

After configuring the print server role, you can do the following:

1. Use a browser to manage printers. You can pause, resume, or delete a print job, and view the printer and print job's status.

2. Use the new standard port monitor, which simplifies installation of most TCP/IP printers on your network.

3. Use Windows Management Instrumentation (WMI), which is the management API created, by Microsoft that enables you to monitor and control all system components, either locally or remotely. The WMI Print Provider enables you to manage print servers, print devices, and other printing-related objects from the command line. With WMI Print Provider, you can use Visual Basic (VB) scripts to perform administrative printer functions. For more information, see Windows Management Instrumentation Command-line (WMIC) tool.

4. Print from Windows XP clients to print servers running Windows Server 2003 by using a Uniform Resource Locator (URL).

5. Connect to printers on your network by using Web point-and-print for single-click installation of a shared printer. You can also install drivers from a Web site.

Application server role overview

An application server is a core technology that provides key infrastructure and services to applications hosted on a system. Typical application servers include the following services:

1. Resource pooling (for example, database connection pooling and object pooling) 2. Distributed transaction management 3. Asynchronous program communication, typically through message queuing. A just-in-

time object activation model


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4. Automatic XML Web Service interfaces to access business objects 5. Failover and application health detection services 6. Integrated security

The Windows Server 2003 family includes an application server that contains all of this functionality and other services for development, deployment, and runtime management of XML Web services, Web applications, and distributed applications.

When you configure this server as an application server you will be installing Internet Information Services (IIS) along with other optional technologies and services such as COM+ and ASP.NET. Together, IIS and the Windows Server 2003 family provide integrated, reliable, scalable, secure, and manageable Web server capabilities over an intranet, the Internet, or through an extranet. IIS is a tool for creating a strong communications platform of dynamic network applications.

Mail server role overview

To provide e-mail services to users, you can use the Post Office Protocol 3 (POP3) and Simple Mail Transfer Protocol (SMTP) components included with the Windows Server 2003 family. The POP3 service implements the standard POP3 protocol for mail retrieval, and you can pair it with the SMTP service to enable mail transfer. If you plan to have clients connect to this POP3 server and download e-mail to local computers by using a POP3 capable mail client, configure this server as a mail server.

After configuring the mail server role, you can do the following:

1. Use the POP3 service to store and manage e-mail accounts on the mail server. 2. Enable user access to the mail server so that users can retrieve e-mail from their local

computer by using an e-mail client that supports the POP3 protocol (for example, Microsoft Outlook).

Terminal server role overview

With Terminal Server, you can provide a single point of installation that gives multiple users access to any computer that is running a Windows Server 2003 operating system. Users can run programs, save files, and use network resources all from a remote location, as if these resources were installed on their own computer.

After configuring the terminal server role, you can do the following:


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1. Confirm Internet Explorer Enhanced Security Configuration settings. 2. Centralize the deployment of programs on one computer. 3. Ensure that all clients use the same version of a program.

In addition to configuring a terminal server, you must install Terminal Server Licensing and configure a Terminal Server License Server. Otherwise, your terminal server will stop accepting connections from unlicensed clients when the evaluation period ends 120 days after the first client logon. For more information about Terminal Server Licensing, see Terminal Server Licensing.

Remote access/VPN server role overview

Routing and Remote Access provides a full-featured software router and both dial-up and virtual private network (VPN) connectivity for remote computers. It offers routing services for local area network (LAN) and wide area network (WAN) environments. It also enables remote or mobile workers to access corporate networks as if they were directly connected, either through dial-up connection services or over the Internet by using VPN connections. If you plan to connect remote workers to business networks, configure this server as a remote access/VPN server.

Remote access connections enable all of the services that are typically available to a LAN-connected user, including file and print sharing, Web server access, and messaging.

After configuring the remote access/VPN server role, you can do the following:

1. Control how and when remote users access your network. 2. Provide network address translation (NAT) services for the computers on your network. 3. Create custom networking solutions using application programming interfaces (APIs).

Domain controller role overview

Domain controllers store directory data and manage communication between users and domains, including user logon processes, authentication, and directory searches. If you plan to provide the Active Directory directory service to manage users and computers, configure this server as a domain controller.

Important Notes:

You cannot add the domain controller role to a certification authority (CA). If your computer is already a CA, the domain controller role is not available in the Configure Your Server Wizard.

Computers running Windows Server 2003, Web Edition, cannot function as domain controllers.


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After configuring the domain controller role, you can do the following:

1. Store directory data and make this data available to network users and administrators. Active Directory stores information about user accounts (for example, names, passwords, phone numbers, and so on), and enables other authorized users on the same network to access this information.

2. Add additional domain controllers to an existing domain to improve the availability and reliability of network services.

3. Improve network performance between sites by placing a domain controller in each site. With a domain controller in each site, you can handle client logon processes within the site without using the slower network connection between sites.

DNS server role overview

The Domain Name System (DNS) is the TCP/IP name resolution service that is used on the Internet. The DNS service enables client computers on your network to register and resolve user-friendly DNS names. If you plan to make resources in your network available on the Internet, configure this server as a DNS server.

Important Notes:

If you plan to include computers on the Internet on your network, use a unique DNS domain name.

After configuring the DNS server role, you can do the following:

1. Host records of a distributed DNS database and use these records to answer DNS queries sent by DNS client computers, such as queries for the names of Web sites or computers in your network or on the Internet.

2. Name and locate network resources using userfriendly names. 3. Control name resolution for each network segment and replicate changes to either the

entire network or globally on the Internet. 4. Reduce DNS administration by dynamically updating DNS information.

DHCP server role overview

Dynamic Host Configuration Protocol (DHCP) is an IP standard designed to reduce the complexity of administering address configurations by using a server computer to centrally manage IP addresses and other related configuration details used on your network. If you plan to perform multicast address allocation, and obtain client IP address and related configuration parameters dynamically, configure this server as a DHCP server.

After configuring the DHCP server role, you can do the following:


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1. Centrally manage IP addresses and related information. 2. Use DHCP to prevent address conflicts by preventing a previously assigned IP address

from being used again to configure a new computer on the network. 3. Configure your DHCP server to supply a full range of additional configuration values

when assigning address leases. This will greatly decrease the time you spend configuring and reconfiguring computers on your network.

4. Use the DHCP lease renewal process to ensure that client configurations that need to be updated often (such as users with mobile or portable computers that change locations frequently) can be updated efficiently and automatically by clients communicating directly with DHCP servers.

Streaming media server role overview

Streaming media servers provide Windows Media Services to your organization. Windows Media Services manages, delivers, and archives Windows Media content, including streaming audio and video, over an intranet or the Internet. If you plan to use digital media in real time over dial-up Internet connections or local area networks (LANs), configure this server as a streaming media server.

After configuring the streaming media server role, you can do the following:

1. Provide digital video in real time over networks that range from low-bandwidth, dial-up Internet connections to high-bandwidth, local area networks (LANs).

2. Provide streaming digital audio to clients and other servers across the Internet or your intranet.

WINS server role overview

Windows Internet Name Service (WINS) servers map IP addresses to NetBIOS computer names and NetBIOS computer names back to IP addresses. With WINS servers in your organization, you can search for resources by computer name instead of IP address, which can be easier to remember. If you plan to map NetBIOS names to IP addresses or centrally manage the name-to-address database, configure this server as a WINS server.

After configuring the WINS server role, you can do the following:

1. Reduce NetBIOSbased broadcast traffic on subnets by permitting clients to query WINS servers to directly locate remote systems.

2. Support earlier Windows and NetBIOSbased clients on your network by permitting these types of clients to browse lists for remote Windows domains without requiring a local domain controller to be present on each subnet.

3. Support DNSbased clients by enabling those clients to locate NetBIOS resources when WINS lookup integration is implemented. For more information, see WINS lookup integration.


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Part II: Lab Guide Cabling Cabling is a process of connecting the cables with its connectors. There are different kinds of cabling. The main two kinds of cabling are listing below: 1. Parallel or Straight through Cabling: - It is IEEE (Institute of Electrical & Electronic

Engineers)-802 Standard cabling used for the different devices, such as Switch or Hub to the PC. Below is example of IEEE 802 Standard of Cabling: (100 Mbps)

2. Crossover Cabling: - The crossover cabling is used to connect the same devices such as from one Computer to another Computer, from one hub to another hub or from switch to switch.

Pin Wire Colors on End 1 Wire Colors on End 2 Formula 1 Orange White Green White 1 goes to 3

2 goes to 6 3 goes to 1 6 goes to 2

2 Orange Green 3 Green White Orange White 4 Blue Blue 5 Blue White Blue White 6 Green Orange 7 Brown White Brown White 8 Brown Brown

Physical Network Setup 1. Two or more systems present with Ethernet Controller (LAN Card) 2. To establish the Network only in 2 systems then have a crossover cabling and to establish

Pin Wire Colors on End 1 Wire Colors on End 2 Assignment 1 Orange White Orange White Transmit + (TX+) 2 Orange Orange Transmit - (TX-) 3 Green White Green White Receive + (RX+) 4 Blue Blue Reserved 5 Blue White Blue White Reserved 6 Green Green Receive - (RX-) 7 Brown White Brown White Reserved 8 Brown Brown Reserved


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the Network in more than two systems with the help of central connectivity device (Switch/Hub/Router) then have parallel cabling for it.

3. Connect the one end of cable to the Switch/Hub/Router and another end of cable to the system NIC.

4. Now start the system and assign the Network Name, Workgroup, IP Address, and its Subnet Mask.

Establishing a Peer to Peer network (workgroup)

Configuring IP Address and Subnet Mask 1. Right click on my network places. 2. Click on Properties 3. Right Click on Local area Connection 4. Properties

5. From the list double click on Internet Protocol. 6. Select option use the following IP address and enter

an IP address and press tab to auto set the subnet mask

7. Click ok then choose option to show icon to get the networking icon on the system tray.

Examples: Computer Name IP Address Subnet Mask Gateway DNS Server Com1 192.168.1.2 255.255.255.0 Gateway should

be same for all Computers. (For ex: 192.168.1.1)

DNS Server address should be same IP address for all Computers of Domain Server Computer

Com2 192.168.1.3 255.255.255.0 Com3 192.168.1.4 255.255.255.0 Com4 192.168.1.5 255.255.255.0 Com5 192.168.1.6 255.255.255.0


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Setting a Workgroup and Computer Name: 1. Right click on my computer select properties.

2. In computer name tab click on change button

3. Here select the workgroup option and type a workgroup name for the network.

4. After settings the workgroup name it is necessary to restart the computer for the new settings to take effect.

Here we can set a name to

represent this computer in

the network

Here we have to set the

workgroup name.


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Checking the Connectivity from DOS (Net DOS Command) Click on Start/Run/Type CMD/ok. Type the following DOS Commands

Hostname: - It displays the name of Computer. Syntax: Hostname Eg: - C:\>Hostname Syntax: Net View \\Computer Name Enter. Eg: - Net View \\Server

Net User: - This command displays the list of the user currently available on the system. Syntax: Net User /Options

a. Using the following syntax we can create the user from the command prompt. Syntax: Net User [Password] Eg:-C :\>Net User Rabin password /Add

(Here, the User Name is Rabin and Password is password). b. Using the following syntax, the User Name can be deleting.

Syntax: Net user Eg:- C:\>Net User Rabin/Delete

Net View: - Displays a list of Computers in a specified Workgroup or the shared resources available on a specified Computer.

Ipconfig:- This command displays the IP address, Subnet Mask and Connection specific, DNS etc.

Syntax: Ipconfig /Options Eg:- C:\>Ipconfig /All (Displays the full configuration information)

Ping:- This Command checks the connectivity between the Systems on the Network. Syntax: Ping Enter. Eg:- C:\>Ping Com1/C:\>Ping 192.168.0.1 .

Net Send:- Sends messages to other users or computers on the Network, by using Computer Name or IP Address. To send message one computer to another computer, the Messenger Service must be running to receive messages computer. To start Messenger Service, Follow the steps:

I. Click on Start/Administrative Tools/Services or Start/Run/type Services.msc/ok. II. Select Messenger service & Right click over it.

III. Select Startup Type/Automatic/Start/Apply/Ok Syntax: Net Send Computer Name/ IP Address Message E.g:- c:\>Net Send Com1 hi , Net Send 192.168.0.1 hi

Instead of Network Name or the IP address, specifying the * mark will send the message to all the hosts on the Network.

E.g:- c:\>Net Send * hi Net Share:- Displays the list of shared drives and the folders on the system.

Syntax: Net Share E.g:- C:\>Net Share

Arp a : show the ARP table (IP Address and MAC Address)


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Syntax: arp -a E.g:- C:\>arp -a

Getmac: show the physical address (MAC Address) Syntax: getmac E.g:- C:\>getmac

SHARING It is a process to make drive or folders accessible with the Computers on the Network. A file can be shared automatically when it is inside a shared folder. There are two kinds of sharing:

a. Visible Share: - The visible share can be viewed from any Computer on the Network. b. Hidden Share: - To view the hidden share, we need to specify the share name followed

with '$' sign. All the hard disk drives are the default hidden share. First method:

Right Click on a folder and select sharing and security

Select option, share this folder as and type a share name for the folder.


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By default shares are created with read only permission To assign different permission:

Click on the permissions button and selecting the required permissions.

Second Method: Right Click on My Computer select Manage.

Type the share name

for the folder here.

Click here for setting

permissions.

This is used for

offline caching.


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Expand shared folders. (From here we can also view list of all shared folders in the computer). Right click on Shares | New File Share | Next.

In the Welcome Screen click Next to continue.


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Click on browse to choose the folder to share. Then enter a share name for the folder and a share description if necessary | Next.

Then select the permission level for the folder. This will decide how users will interact with the folder.


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To set different settings select option Custom settings and click on custom button shown in the above diagram. Then set the required permissions and click on Ok | Next | Finish.

Accessing shared folders (First method): To access a remote resource we can use the My Network Places icon on the desktop.

Open My Network Places and click on option View Workgroup Computers option.


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Then a list of all available computers in the network will be shown and from here we can access the resource of any computer.

Second Method: For Visible Shared Drive or Folder:

Go to Run Window & type the following Syntax: Syntax: \\Computer Name\Shared Drive or Folder Name e.g.\\Server\Backups (Here, Server is the Computer Name & Backup is the Shared Drive or Folder name).

For Hidden Shared Drive or Folder: Go to Run Window & type the following Syntax: Syntax: \\Computer Name\Shared Drive or Folder Name$ e.g.\\Server\D$ (Here, Server is the Computer Name & D$ is the Shared Drive).

Viewing the Shared Drives or the Folders: a. Right click on My Computer.

Computers available in the network. Double

click on a specific computer to open it.


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b. Click on Manage. c. Click on Shared Folders. d. Click on Shares.

Removing the Sharing a. Right click on 'My Computer'. b. Click on Manage. c. Click on Shared folders. d. Click on Shares. e. Right click on the drive or the folder to remove the sharing. f. Click on 'Stop Sharing'. g. Click on 'Yes'.

Network drive: Network drives help us to connect a remote computers shared folder on to our computer directly like a drive in My Computer. This provides faster access to remote shares and makes it easier to save data into these folders. This setting has to be done individually on all computers. Steps:

Right Click on My Network Places select option Map Network Drive.

Then select a drive letter for the network drive (any) and enter the path of the remote folder. Ex: \\computername\Foldersharename


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Then click on Finish to connect. Then this folder will be shown as network drive in My Computer.

Steps: (To disconnect Network drives) Right Click on My Network Places select option Disconnect Network Drive.


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Then in the list select the network drive to disconnect Ok. Then it will be removed from My Computer.

Enabling Remote Desktop Connection Remote desktop can be used to connect to another (remote) computers operating. This

allows us to use all resources of the remote computer such as installed programs files, practically everything. This requires 8 MB of RAM per connection. But windows XP only allows a single connection and when a remote user connects on the computer the local computer will be logged off meaning only one connection cab be used at a time. But Windows server allows unlimited connection. Steps: 1. First Remote Connection must be enabled on

the Host computer. Right Click on My Computer properties.

2. In the remote tab select option enable users to connect to this computer remotely. OK

NOTE: By default only Administrators can use remote connection but other users can also be defined by clicking on Select Remote users button. Then click on Add and add the required users.

3. Next from any client computer go to start programs accessories communications select remote desktop connection and type the IP Address of the remote computer and click on connect.


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4. We can click on options and select on Save as to create a shortcut for the connection.

NOTE: By default after we connect only the remote computers drives will be shown, to use our local drives we can click on options and in local resources tab click on disk drives. Applying DHCP on Workgroup Network: Dynamic host Configuration Protocol can be used to assign Automatic (Dynamic) IP Addresses to all computers in the network. But for this at least one computer must have windows server operating system installed and it must be configured as a DHCP server. Steps: 1. First DHCP must be installed on the Server. Open control panel | Add\Remove programs |

Select option Add\Remove windows components.


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2. From the list double click on networking services and select DHCP and click ok | Next to install. (We will also require the server CD during installation).


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3. Then DHCP can be found in control panel | Administrative Tools | DHCP.

4. Open DHCP | Right click on the computer name and select option New Scope.

5. In the Welcome screen click Next to continue.


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6. In the Scope name screen type a name for the DHCP scope and if necessary a description also | Next.

7. Then enter the range of IP addresses to be assigned to computers. This should be set according to the number of computers in our network. Also verify that the subnet mask is correct | Next.

Example: Start IP address = 195.100.100.1 and End IP address = 195.100.100.100. This will assign 100 automatic IP address to 100 clients.


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8. Then in the exclusion screen enter any IP addresses in the range which have already been used. This is used to prevent duplicate IP addresses on the network | Next.

9. Then in the Lease Duration screen enter for how in days can a computer use an automatic address | Next.

NOTE: This can be set according to our requirement. After a computer has totally used its IP address for the specified number of days it will need to renew its IP address by going to My Network places | Properties | Right click on Local area connection and select Repair.


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10. Then select option Yes, I want to configure these options now | Next.

11. Next the router (default gateway) screen will be displayed. If an ICS server is setup to share internet connections then here type the IP address of the ICS server. | Next.


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12. Then the Domain Name and DNS Servers screen will be displayed. IF using a domain network here we can add the details of the Domain controller | Simply click Next.

13. Then in the WINS servers screen will be shown | Next.


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14. Then select option Yes I want to activate these options now | Next | Finish.


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Troubleshooting a Network The following sections list a series of common networking problems along with solutions

that can usually set things right again. Problem: We can not ping any computers in the network Solution: By default the Windows Firewall is enabled in windows and this should be disabled in a workgroup network or else computers might not be able to communicate. Steps:

1. Go to My Network Places Properties Local area Connection Properties. 2. In the Advanced Tab click on settings select OFF to disable the Windows Firewall.

Problem: Duplicate computer names. Solution: Make sure that every computer on the network has a unique name. Otherwise, you'll get an error message when you reboot the workstations with networking cables attached. (You can change the computer name from the System applet of the Control Panel, although you must restart the system for it to be effective.) Problem Different workgroup names. Solution

Make sure every computer that's supposed to be working together has the same workgroup name. The Windows My Network Places icons display computers by workgroup name. Problem Shared resources are not available. Solution

Make sure that shared resources have been set for any servers on your. If you can't share a resource ensure that File and Printer Sharing has been installed.


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Problem All settings are correct but no computers are shown in My Network Places. Solution

This can be because the security settings of the windows operating system has been set correctly. These settings need to be changed in order for the computers to be shown. Check these settings on all computers in the network. Steps:- 1. Open Control Panel Administrative Tools Local Security policy. 2. Expand Local Policies. 3. Select Security Options. Here set the following settings:

a. Network Access: Allow anonymous SID/Name Translation Enabled. b. Network Access: Do not allow anonymous enumeration of SAM accounts

Disabled. c. Network Access: Sharing and Security model for local accounts. Classic.

4. Then restart the computer. Now computers will be shown in My Network Places. Problem A user can't access any shared resources (but others can). Solution

First, have the user log off and log back on. Next, check cable connections a loose or disconnected RJ-45 cable affects only the computer (or hub) using it. If a Category 5 UTP cable seems to be connected tightly but the user still can't get on the network, check the cable with a cable tester or replace the cable. Problem Blank Passwords dont work Solution

In a peer to peer network when we first access computers or shared folders we will be asked for a user name and password here we need to enter the remote computers user name and password to gain access. The user must have a password set because blank password dont work in a workgroup network. Problem Message about duplicate IP addresses can't connect to anything. Solution

Duplicate IP addresses disable TCP/IP networking. Check the IP Addresses of all computers in the network. We need to make sure that a same IP Address is not assigned to nay computers in the network. Problem No error message can't connect to Internet or other computers. Solution

Check the router, switch, or hub used to connect the computers to each other and the Internet. It needs to be powered, and the data cables must be properly connected between it and each computer.

If your network uses DHCP to dynamically assign IP addresses and the router has lost power or connection, users won't be able to get IP addresses. Restart the router, and have all users log off and shut down. When they restart their systems, they should be able to obtain valid IP addresses and connect with each other.


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CLIENT SERVER NETWORK

Active Directory:

Active Directory is the main database file which stores all the information about the users. It

starts and blocks the different kinds of services such as the Group Policy, DHCP, DNS, IIS, and Mail Server

etc. After installing Active Directory in a Networked Computer that Computer becomes the Domain

Computer, Server Computer or Domain Server.

Creating A Domain Controller

1. Set a valid IP address on the computer which will be made the domain controller. We should set the

same IP address in the DNS server field.

2. Next open Control Panel Add\Remove Programs Then select Add\Remove windows

components From the list open networking services then select DNS ok Next to install the

DNS service.

NOTE: We will require the windows server CD during installation.

3. Next go to RUN and type dcpromo and press enter to begin the active directory installation.

4. In the welcome screen simply press next to begin installation.


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5. Next the operating system compatibility screen will be displayed giving information that Windows 95

and Windows NT are not compatible with the domain network. NEXT

6. Next the domain controller type screen will be displayed with 2 options:-

a. Domain controller for a new Domain: Select this option when creating a new server.

b. Additional domain controller for an existing domain: This option is used to create a backup

server for the domain.

A. Select option 1 and click Next.


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7. Next the Create a domain screen will be displayed with 3 options:-

A. Domain in a new forest: this option is used when creating a new domain network.

B. Child domain in a existing domain: This is used to create sub domains (child domains).

C. Domain tree in an existing forest: This option is used to create a separate domain in the

existing domain forest.

Select option 1 and Next.

8. Next the new domain name screen will be displayed here set a name for our domain (For ex:

aptech.com.) NEXT


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9. Next the NETBIOS name screen will be displayed this is auto set so simply click Next.

10. Next the database and log folders location screen will be displayed here if we want we can set a new

location. It is best to use the default location. Next


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11. Next the Shared System Volume screen will be displayed; here we can select the location to store

the replication data used when multiple servers exist in the domain. It is recommended to use the

default location. Next

12. Next the DNS registration screen will be displayed simply use the default setting and click Next.


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13. Next the permissions screen will be displayed with two options:

A. Permissions compatible with pre-windows 2000 server operating system: Use this option if

there are old version windows in the network. This makes security weak not recommended

B. Permissions compatible with only windows 2000 and 2003 server operating system: This makes

security very tight and old version windows cannot function in the domain.

Select the required option Next

14. Next the directory services restore mode screen will be displayed here we can set a password for

this mode; this password is different from the log in password. Next (this can be left empty).


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15. Next the summary screen will be displayed showing information of all options that we have selected

if all is correct then click next

Then the Active directory Installation will begin.

After installation completes click finish and then click the restart now option.


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Adding Clients to the Domain Controller (Domain Registration)

It is a process of connecting the Client Computers with the Domain Controller Computer. After

registering the Client Computers with the Domain Controller then the Client Computers are called

Domain Members. After registration, can be login on the Client Computers in two ways: one is Local and

another is Domain Member when logged in as a Domain Member, can be using only the services that

are provided by the Domain Controller.

1. Set a valid IP address on each client computer and in the DNS server field type the IP address of

the server.

2. Next go to My Computer properties Computer Name Click on Change Select option

Domain and type the domain name (aptech.com) and click Ok.

3. We will need to enter the administrator user and password to change these settings.


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Then a Welcome to the APTECH domain message will be displayed here click OK

Then a message saying you must restart this computer will be displayed here click ok and close all

properties page and select option restart.

4. Then restart the computer. Then in the Log On dialog box use a domain user account to log on

and in the log on to option select the domain name to access the domain resources.

Disjoining from Domain:

a. Go to the properties of TCP/IP and remove the IP from the Preferred DNS Server.

b. Go to the properties of My Computer.

c. Click on Computer Name; Tab.

d. Click on Workgroup radio button.

e. Click on OK.


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f. Type the name of Administrator and Administrator Password.

g. Click on OK - Restart the System.

Disabling the Password Policies

a. Start/Program/Administrative Tools/Domain Security Policies.

b. Click on Account Policies.

c. Click on Password Policies.

d. Double click on the Enforce Password History/ specify the character '0'

e. Double click on the Maximums Password Age/ specify the character '0'

f. Double click on the Minimum Password Age/ specify the character '0'

g. Double click on the Password Length/ specify the character '0'

h. Double click on Password Must Meet Complexity Requirement/ select Disable.

Notes: To take full effect recently open Command Prompt or run command, type Gpupdate /Force &

press enter or restart the Computer.

Creating Organizational Unit:

Organizational Units are used for better arrangement of users and groups and also they can be used to

apply Group Policies to multiple objects at once or separately as per the requirement.

1. Open Active Directory Users and Groups Right Click on the Domain Name New

Organizational Unit.

2. Then enter a Name for the Organizational Unit OK


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3. Now we can right click on the OU and create new users or groups inside it. We can also select

and drag already created users and groups into the OU.

4. To apply group policy on the OU: open its properties and in the Group Policy Tab and Click New

to create a new policy

5. Then click on edit to set the required policies.


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Move the Users to any Container

a. Go to Active Directory Users and Computers.

b. Select the users name that you have to move.

c. Right click and then choose move.

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