Network is the communication of more than two computers. This communication can be between two computers on different continents over the internet, or between two computers in the same space. If these computers are located in the same local area, this network is called a local area network. For this purpose, ethernet cards and necessary cables must be provided on every computer. As the LAN grows, units such as HUB and Server will be added to increase the speed and capability of the LAN. WHAT YOU CAN DO WITH LAN The main benefit of LAN is the sharing of data. However, you can use it in many different ways. For example, a single printer can be used by all office workers in the offices, communication between all users can be made on the computer screen, incoming faxes can be displayed on the users' screen and each user can receive faxes from their own system, and an application can be used by multiple users while working on the server. Home and office users can connect multiple computers to the internet, send and receive e-mails and even play games with a single internet connection. LAN TYPES: LAN between two computers: This smallest type of LAN is also the most economical. It is enough to connect an Ethernet card to both computers and connect these cards with a CAT5 standard cross cable. Between more than two computers LAN with BNC: There are two ways to follow if the number of computers is more than two. The first one is to connect ethernet cards in all computers in series with BNC cables. In this system, each computer is connected to the next one and a chain is established. A piece called the finisher is placed at the beginning and end of the chain. However, this system, which is quite old, has many disadvantages. The first is the failure to connect 100Mbit with BNC cables. Another disadvantage is that a break at any point in the cable network or failure causes the entire LAN to be disconnected. However, if you want to install a LAN that will cost between three and four computers, you can choose this system. LAN with more than two computers installed with CAT5: Today, the more common system is to connect all computers to a HUB with CAT5 type cables. In this system, if you want, each workstation can be connected to the same HUB to communicate with each other, or a server can be connected to HUB to share information over the server. This system can operate at speeds between 100Mbit and 1Gigabit, as each machine is connected to the HUB with a separate cable, the fault in one of the connections does not affect the others. In addition, data transmission is designed according to this system in most of the programs available over the network today. Some commercial programs such as Logo or ETA do not work on the BNC system. (This last sentence seemed quite unreasonable to me, I've seen these programs running at BNC before, And why shouldn't he work?
NSTALLING A LAN: Cabling The first thing you need to do when setting up your LAN is laying the cables. This is a job that needs a lot more attention than you think. When deciding where to route your cables, make sure that they are not stepped on, and that they pass a minimum distance of 10 cm to your power line. Also note that no heavy objects should be placed on the cable. For a healthy structure, it is the best solution for your cables to pass through the channels under the floor or on the side of the wall. The channels passing under the ground can be considered only in a newly constructed or undergoing renovation as more architectural processes are required. However, the plastic ducts leading from the wall edge offer both a more practical and a more economical solution. The cables used in networks are different from other cables. The most important problem in laying these cables is the installation of connectors. If the computers are close to each other, you can use 3 or 5 meter prefabricated cables. However, you may need to connect your own connectors to the end of your own cables for greater lengths. When connecting the connectors at the ends of the CAT5 cables, the colored thin wires in the harness must be lined up and the connector must be tightened with a special pliers. Therefore, it is very easy to determine the length of the cables and have them made to order. If you have the possibility to install the connectors yourself, make sure that the connectors are well tightened. It's easier if you're going to set up a LAN with a BNC cable in series. Because it is possible to connect the connectors of the BNC with a normal pliers. But this is a bit difficult with normal pliers, as the BNC connectors are designed to be tightened with the help of the special pliers mentioned earlier.
SETTING ETHERNET CARDS Ethernet cards enable the computer to communicate with the LAN. Inserting these cards is no different from other cards. If you want to choose 10Mbit or 10 / 100Mbit ethernet card, the card you will find will probably be PCI. The first thing you need to do is open a computer case and select an empty PCI slot. Remove the metal part covering the back of this housing; insert your card vertically into the slot and replace the screw that secures the back of the card. That's all. Then you have to introduce the card to windows. After inserting the card and turning on your PC, Windows will recognize that it recognizes your new card through Plug and Play and ask you for the location of the drivers. Insert the driver floppy disk or CD that came with the card into the computer and show Windows where the drivers are. After installing the drivers, Windows will prompt you to turn the system on and off. After re-opening, you need to do from the Start menu, select Settings - Control panel. Switch to the System Device Manager tab here. In the list here you will see a line named Network Adapters. By pressing the plus sign next to it, you will see the ethernet card you just installed. The yellow exclamation mark or the red cross over the icon next to your card indicates that there is a fault in your ethernet card's drivers. In this case, you should consider reinstalling the drivers or finding a newer driver. If there is no sign, your Ethernet will probably work. The next step is to make the Network settings. Enter the control panel and double-click the Network icon and enter the network settings. In this window you will see the name of your ethernet card again. This is the configuration window. First you have to select the type of cilent of your network, then the protocol which is the language in which this network will speak. The network type of the Windows 95 PC is Client for Microsoft Network. Click on add, then select Client and Microsoft, then scroll to Client For Microsoft and select it. Then you can select one of the protocols, TCP / IP, Netbeui and IPX / SPX from Microsoft. You have a chance to mark them all. However, the system will slow down by 3%. After returning to the configuration window, you will need to identify your PC to the other PCs in the identification tab. In the Computer name section, type any name you give to your system without using Turkish characters. Remember to give the same workgroup name to all the computers that you want to include in the same group only when the same case names the workgroup. Computer description may not be filled. You can now press Enter. The files will be loaded and Windows will ask you to turn the system on and off. When Windows reboots, it will prompt you for a password to enter the Microsoft Network. Please enter a password you want to be careful not to use Turkish characters. After pressing Enter, it will prompt you to type your password again. Repeat your password.
INSTALLATION OF CABLES One of our last operations is the installation of cables. If you are using two computers, connect your CAT5 Cross cable to the slots on the two computers' ethernet cards. If you have more than two computers, you need a HUB. HUB prices have fallen considerably lately. For a small network you can find a 10Mbit HUB for under $ 60. HUBs of 5, 8, 16, etc. such as the number of users. If you are going to add a few more computers to the system in the future, it would make sense to buy your HUB from the dealer accordingly. However, if your HUB is out of space and you have a new computer you want to connect, you can increase the number of users by taking another HUB and connecting the two HUBs again with the help of CAT5 cable. Connecting your computer to HUB is very easy. Each computer's ethernet card with the help of CAT5 cables to enter the HUB one by one. It doesn't matter in what order you entered the computers. In addition, you do not have to do anything other than plug in the HUB with the adapter. SHARING Now we can consider sharing your files or printers. To do this, you should still access the Network from the Control Panel and select Add, File and Printer Sharing for Microsoft Networks, which includes your file and printer sharing from the Service. From the next window you have the chance to share only files or only your printer. Press OK twice, you need to restart your PC after the files are loaded. Type your password and log in to the network and then click on the right mouse button from My Computer to select your share. In the Share Name section of the window, specify what other computers would like the name of your hard drive to be. You can set a read-only restriction to those accessing your hard drive from the access type section at the bottom. In this case, no one can make changes to your hard-disk, can not delete any files, you can only copy files from your machine. Note that this option also prevents viruses from entering. However, if you wish, you can grant the Full Access right so that you can do what you want on the hard drive. Of course you don't have to give access to your entire hard drive. You can also do the above-mentioned operations to any folder on your hard drive. To share your printer, all you need to do is select Settings from Start and then select printers. In the window that opens, right-click the printer you want to share and select the share. From here you can specify the printer name and share it. After that you can start using your network. You can see shared files on other computers by clicking the network neighbors icon on the desktop. You can also share your Internet access by adding a proxy program such as WinGate to this system. However, if you want to edit different e-mail accounts with an Exchange Server or you can easily send and receive faxes from every computer with Fax Server, you will need a server. If you want to assign one of the computers you use as a server or a separate computer. However, you will need an operating system like NT, which is more network-friendly, and you will need professional help. NETWORK SELECTION AND INSTALLATION Before establishing a computer network, we need to make certain decisions about design. If you are planning a small network, this process will be shortened, but it will not lose its importance. First, you need to do a feasibility and system analysis to determine what goals you want to achieve with your network. Such a study will certainly help you in choosing the right kit. APPOINTMENT OF ADMINISTRATOR At this stage, it is wise to appoint a part-time or full-time network administrator and give him the necessary authority. In terms of network efficiency, reliability and security, it is useful to gather the responsibility in one place. BASIC INFRASTRUCTURE DECISIONS You are now in the process of creating your network project. The most tedious and tiring part of this work is the laying of cables. However, carelessness at this stage may be an expensive source of headache in the future. So what are the options? Here is a small list: Coaxial cable or unshielded telephone cable (UTP) uses 10 MB / s or 100MB / sec Ethernet (also known as 10BaseT) 4 or 16MB / sec Token Ring 100MB / s speed fiber-optic distributed or copper distributed data Interface (FDDI-Fiber Distributed Data Interface- Copper DDI) Asynchronous Transfer Mode (ATM), 155 MB / sec Which is the best option? It's probably 10 MB / s of category 5 UTP Ethernet, because this system is quite cheap and easy to expand. You can buy Ethernet NICs (Network Interface Cards) for 100-200 dollars. If you make sure that the cards can be set via software, you will not only be able to open PCs with each change, but also eliminate the possibility of losing switch settings. In addition, the card you purchase must comply with the Novell NE2000 standard and should be sold with drivers for the most common operating systems. Most of the technicians you work with will be experienced in NIC. You can connect your NICs with the help of coaxial cables, but your system will be vulnerable to malfunctions in the cables and the entire network will be out of use for the smallest damage. Catagory 5 type UTP systems are faster and more reliable since all cables are collected in a single box. A fault in one of the cables affects only one PC. One of these boxes, the Hewlett-Packard J2610A, is one of the products with the highest price efficiency. Designed for small workgroups, this eight-door box is available for $ 250-350. When you receive the box, all you need to do is connect the cables from the NICs to the box via the front panel. Then, you can share printers and hard disks using Windows For Workgroups. In addition, if you have two separate workgroups and want to combine them, simply connect any port of one box to the first port of another box and press a button. The back panel features a module slot for coaxial, even fiber-optic cable connections, and a card slot for connecting a PC that can manage the entire network. With this PC, you can see the terminals connected to the box, examine and change the status of a gate, view LAN traffic and overload data, and reset the box. Other wiring diagrams can't handle Ethernet in terms of cost, assuming you don't have special needs. Designed by IBM, the Token Ring system has several advantages. This restructuring terms of the Stars in the form of 4MB / Although sec to 10MB / sec Ethernet up to running speed (if networking is very installed even faster. The cost of this system is more secure than coaxial Ethernet of keeping quite high. 100MB / sec Ethernet system, If your bandwidth doesn't matter, don't pay much attention, but let your cables run at 100MB / s for the possibility of future expansion.It's more effective to solve capacity problems by adding a new box. Currently, three standards compete for fast Ethernet and are likely to make the wrong choice. Also, when you make a choice, ATM, which is a new technology, may have thrown all of them into checkers. No need to deal with Fiber-Optic technology: copper UTPs are enough for 100MB / s Ethernet and even 155MB / s ATM.
OTHER UNIT? Is it yourself? You can reduce the cost by setting up your system yourself, but you can lose more than you earn if your cable network is unreliable. The smartest way to follow is to first learn how to set up the system and then call the experts and let them set up the system. Thus, you will be able to understand what they tell and if they are competent. It will also be a very useful step to meet with the companies that you have chosen from experts. Don't save money when buying cables and connectors. All your work will flow through those thin wires. If you are going to use coaxial cable, choose the best quality T-plugs. If you are going to use the recommended 10BaseT system, select category 5 UTP at 100MB / s; you won't have to replace the cables when the system expands in the future. Do not run the cables from the floor, lay them on the ceiling and lower the cables to all work desks (calculate over time that all employees will join the network). Pour the whole scheme on paper and keep it in place by updating it frequently. PEER TO PEER OR SERVER When you have completed the cabling phase, it is time to determine your network type. Peer-to-peer networks represented by Windows for workgroups are useful on the surface in order to be built using hand-held PCs. You can access the hard disk, CD-ROM drive, or printer of any machine on the network. But the coin also has the other side. The PC you have reached is used twice as much as it is used by someone else. A low-power PC may not be able to handle this load. The owner of the PC with the information you want to access may neglect to back up the data or the machine to which the printer is connected may be turned off. On a separate PC with all operating resources (Novell Netware or WindowsNT), all resources that are common to other alternative Server systems, ie Server. The speed of the network will increase significantly if it is not used to run server applications but is dedicated to file management only. Since all data will be stored in the Server, it will be very easy to back up. The server's power supply may be protected, and may even stand locked in a safe place. OPERATING SYSTEM SELECTION The network operating system must be made entirely dependent on the users network format. The most popular of these systems, Windows For Workgroups, is not as powerful as LANtastics or PowerLan, but has a very popular and extensive support service. Novell, with its 50,000 certified engineers in the field of server networks, holds 72% of the sector. WindowsNT does not have a high market share due to Microsoft's lack of experience in computer networking. The ease of management of the system is also an issue to be considered. For example, although Netware 3 has a very effective security system, it is very difficult to install without the help of additional network management tools, especially on systems with many servers. Too many people will be able to access passwords and directories due to set-up failures. Netware 4 and WindowsNT are good at this, but you need to add an NT server to the system to manage Windows For Workgroups effectively. WHAT APPLICATIONS? There are two ways to run applications: Client Server and File Server. The Client Server separates the user interface of the application from the computing units. You enter your request and the required data from your terminal and they are processed on the server and returned to your terminal. It presents these results to you in the terminal by putting them in a certain shape. Thus, the least amount of data is circulated within the network. Databases are the most important examples of this. File Server applications copy all data to the terminal, process them in the terminal and display the results. These operations are only very useful in low volume systems as traffic is highly concentrated. It is also important that the applications you select are written for a multi-user environment. Pay particular attention to databases that start to run as the user increases. You should also pay attention to the maintenance of your network. Reports on the amount of data processed, errors and security breaches will be very useful. Common data should be automatically backed up without anyone having to remember it. Which equipment? Although PC selection for user workstations does not depend on the operating system and software used, peer-to-peer systems will have better PC capacity. If you are going to buy a server, never settle for at least. Since the speed of the network is directly proportional to the amount of memory, do not save at all in this area. Choose the largest and fastest hard drive you can buy If your network is working well, the demand for the location will surprise you. Although it can serve as any PC server, it is wise to choose only systems that are built for this task. SCSI is much more useful in multitasking environments because it works on the PCI bus and reduces processor load. Select systems that write the stored data to several locations. If you don't spare the money, you can get systems that allow you to replace a failed disk without losing any data and shutting down the server. It would be foolish to invest in an advanced RAID system if your system is powered by a single power supply connected to the common outlet. Always use an uninterruptible power supply and connect the server directly to the mains without plugs. In addition, the server's box can be locked will prevent it from playing with the controls. There may even be a box alarm.
HOW TO SUCCESS If people are still passing data to each other on floppy disks, if they are afraid to write their data to the network, some of them are using their own printers and if the common applications from the server are very small, your network does not respond to your expectations. A successful network is used very intensively without noticing itself. The most ideal indicator of success is the words of an employee: "We do not use a computer network. I keep all my data on my M drive. SPEED TRAPS: Not designed for multi-user systems among the causes of speed problems in applications, too much load on the network, the memory of the server is too small or floppy. system is slow and NICs are slow. BYTE RAID: RAID (Redundant Array of Inexpensive Disks, series of inexpensive disks) act as the error correction mechanism in fast modems. Data is either copied or spread to many discs rather than being written to a single location. When one disk fails, sufficient information is available to compensate for the lack of other disks. POINT TO POINT: ATM (Asynchronous Transfer Mode) connects a point to another by means of switches, just like a telephone exchange; the bandwidth of the network is not shared, and applications with time sensitivity such as image transmission can be given priority. IN CHARGE: Only one person should have access to an entire network. If this is not possible, make sure that routine procedures do not require a public password. WHAT IS TCP / IP? A protocol is a set of rules that regulate commuting messaging between points that provide internet connection in a communication process. These protocols occur between hardware and software that communicate with each other. For communication to occur, each element must have accepted and implemented this protocol. TCP / IP is a family of protocols in which more than one hundred information communication protocols are collected. The most important of these is TCP (Transmission Control Protocol) and IP (Internet Protocol) is named for this. Regardless of the protocol used in a computer network, computers actually recognize and communicate with their physical addresses. This physical address is a 48-bit number that cannot be altered in any way within the network card or any hardware that enables connection to the network. Unlike other computers in the TCP / IP protocol, each computer receives an IP number. Its appearance is “220.127.116.11.. Each computer on the Internet has its own IP number and belongs only to it. IP addresses are in 32-bit order, but are divided into 4 groups of 8 bits for easy readability. They identify the sender and receiver who are exchanging data on the Internet. They always have the sender's IP address when sending data. The address of the recipient is also “domain eki in the address and resolved according to the address. The IP address structure has two parts. The first is the number of a private network to which the computer is connected, and the second is the private number of the computers. When the data passes through routers called Routers during roaming, only the number of this private network is checked. IP addresses are divided into five classes called a, b, c, d, e. Class A addresses are determined by the first t octet ve and must be between 0 and 126. For example, 18.104.22.168 is a class A IP. Likewise, B is determined by the first two octets and the first octet is between 129 and 191. Class C uses the first three octets and the first octet is between 192 and 223. Class D and E IPs are not used because they are for testing purposes only. To give an example, when you connect to the ISP via a telephone line, you join the ISP's network. You are given an address from the previously acquired IP address pool. For example, if your IP address is 22.214.171.124, the class of IP address your ISP receives is C. In other words, the three octets represent the network you are in and the octet at the end represents your computer's current address. ROUTER The router is a hardware or software that is used on the Internet that determines the next destination of packets to their destination. The router connects at least two networks to each other and determines the direction in which the packets will go, depending on the nature and condition of the networks to which it is connected. Routers create a table of information about each possible direction and their status. They perform the routing process by calculating the safest and most cost-effective way of transmitting this information. INTERNET PROTOCOL IP When sending or receiving any data on the Internet, for example an email or website, the messages are divided into small packets. Each packet contains the IP addresses of the sender and recipient. Each packet passes through a computer called “Gateway öncelikle first. This computer reads the address of the recipient on the packet and routes the packets accordingly. This process continues until the computer closest to the recipient's address. This latest computer also sends packets to the receiving computer. These packets, which travel according to the Internet protocol, can reach the recipient in many different ways. Even packages may not reach the recipient when they should be. The purpose of the Internet protocol is to send these packets only. It is the task of another protocol, TCP, to restore packets. DOMAIN NAME SYSTEM Because of the difficulty of memorizing IP addresses, computers are often referred to as “hosts“. This means that each computer on the Internet has an IP address and a host name. However, to ensure communication, these names must be converted back to IP addresses. Therefore, DNS Domain Name System is used to perform this translation. It is a database that hosts every IP address and domain name on the Internet. This system is so established that this database is classified and classified according to certain criteria. The domain name of a computer is name.com. The country code is also added at the end according to the country. For a domain located Each domain has a DNS server. The list of all computers that receive the domain is stored on a server. Or, those ending in ".com" are kept on a DNS server computer in the USA. These addresses are parsed end-to-end. So “name.com.tr ır is separated by name. And it is organized together with other computers of the same name. If there is no country name at the end, which only applies to computers in the United States, it is parsed by looking directly at the ".com" name. These are also called top-level domains. .com commercial companies .edu educational institutions .org non-commercial organizations .net internet backbone networks .gov government agencies .mil military institutions When we enter an address on our computer, this information is transmitted directly to the relevant DNS server. If this DNS server contains the information of this computer, it will immediately forward the IP address of the corresponding address to the DNS client. ARP ADSRESS RESOLUTION PROTOCOL Computers that have IP addresses specified on a local network normally broadcast an incoming broadcast that queries the physical address of the owner of the IP address before it starts messaging. The computer with the IP address sends a message containing its physical address to the client computer, thereby transmitting the actual data through that address. IP ROUTING Routing and sending packets in the net environment is the duty of the Internet Protocol. It compares the information in a routing table by looking at the addresses written on the packets and makes the routing. The task of creating this table is the task of routing protocol. Routing protocol is also available, but only one of them exchanges information between internet routing domains. ICMP Internet Control Message Protocol This protocol serves to alert the sender if an unexpected event occurs during data communication of the internet protocol. To give an example of ICMP messages: Destination Unreachable: This message is used to indicate that the host, the destination, is inaccessible. That is, the network where the receiver is located is undefined or inaccessible. Echo And Echo Reply: These two types of messages are used to determine if the recipient is accessible. The sending computer assigns an echo message containing data to the recipient. If the reply comes from the receiving computer, ie echo reply, it indicates that the receiving computer is accessible on the network. TCP As mentioned before, data is sent in small ways and sent in different ways and in different order. The name of the protocol that provides the sequence of these packets is TCP (Transmission Control Protocol). For example, any data that comes to us is first packaged. The TCP that performs this packaging also enumerates and addresses these packets in sequence and sends them to the IP layer. Now the sending process is only in the hands of the internet protocol. The packages are separated from each other after they leave and follow different directions. When it arrives on our computer, it is TCP which allows us to see these packets as a whole and in full order. At the same time TCP / IP `s to provide the most reliable protocol that performs the function. After a certain portion of the packets have arrived, TCP will send us a confirmation if the packet is intact. If there is a problem with the packages, this confirmation will not come and we will have to send this data from the beginning. In other words, if there is something different from other protocols, we know this and we will complete the communication by sending the gaps again. UDP User Datagram Protocol Unlike TCP, it is a protocol that aims to be less reliable but faster. It is used in some simple prompt and reply processing applications to improve the process faster. Add a port number next to the IP number on the package made by UDP and thus create the sockets required for applications to work. Forming İnternet` TCP / ıp`n some protocols and applications that reside on another layer is as follows: TELNET: "Telecommunication Network" abbreviation of the phrase, a terminal protocol that enables access to other hosts on another host connected and network users FTP: "File Tranfer Protocol Protokol a protocol that allows the user to transfer files between his or her computer and another computer ARCHIE: A tool that allows the user to search for the name of a particular file on all registered anonymous FTP servers. GOPHER: A tool that allows people to search for data repositories using a menu-based and hierarchical interface . SMTP allows mail to reach the e-mail server between e-mail servers on the internet and between e-mail servers from any computer and from any computer. HTTP: Hyp The Hypertext Transfer Protocol baz is the base protocol that provides information exchange over the internet. The information on the WWW is written in HTML format, regardless of the system in which it is used, and each system recognizes this format. FINNER: Used to find out the status of other users or hosts on the Internet. POP: The Post Office Protocol allows a user to receive mail from the POP e-mail server to the client between the e-mail program and the e-mail server, and allow users to manage their own mailboxes. DNS: Domain The Domain Name System düzen regulates the names on the Internet and their IP addresses. It also associates domain names with mail and name servers. SNMP: Simple The Simple Network Management Protocol belir specifies procedures and databases for managing TCP / IP-based network tools. SNMP (RFC 1157) is widely deployed in local and wide area network PING: Pack The Packet Internet Groper ”allows a user in a system to learn about the status of other connected computers and delays in messaging. ICMP uses Echo messages. Whois / NICKNAME: Allows the user to search databases that compile contact information about hakk domains “and“ domains ler on the Internet. TRACEROUTE: It is a tool for tracking and learning the path of packets to another remote computer.