CONFIGURE COMPUTER SYSTEM AND NETWORK Many software products require that the computer has a certain minimum configuration. For example, the software might require a graphics display monitor and a video adapter, a particular microprocessor, and a minimum amount of main memory capacity. When you install a new device or program, you sometimes need to configure it, which means that you need to set various switches and jumpers (for hardware) and to define values of parameters (for software). For example, the device or program may need to know what type of video adapter you have and what type of printer is connected to the computer. Thanks to technological advancements, such as plug-and-play, much of this configuration is now performed automatically. SAFETY PRECAUTIONS RELATED TO NETWORKS SAFETY PRECAUTIONS WHEN USING A LADDER:
SAFETY RULES WHEN WORKING WITH CABLES
Use common sense when installing cables and fixing network problems. Call for assistance for tasks that you cannot do on your own. FIBER-OPTIC SAFETY
Specific types of tools and chemicals are used when working with fiber-optic cable. These materials must be handled with care. CHEMICALS TOOLS The tools used for working with fiber optics have sharp cutting surfaces that are used to scribe glass. Other tools pinch cables with high pressure to fasten connectors to them. These tools can produce shards of glass that can splinter and fly into the air. GLASS SHARDS
HARMFUL LIGHT
NETWORKING DEVICES, MEDIA AND CONNECTOR COMMON NETWORK CABLES TWISTED PAIR UTP vs STP Shielded Twisted Pair (STP)
Unshielded Twisted Pair (UTP)
UNSHIELDED TWISTED PAIR (UTP) SHIELDED TWISTED PAIR (STP) CATEGORY RATING
Some Category 6 cables use a plastic divider to separate the pairs of wires, which prevents interference. COAXIAL CABLE SEVERAL TYPES OF COAXIAL CABLE EXIST:
FIBER OPTIC CABLE Fiber-optic cable can reach distances of several miles or kilometers before the signal needs to be regenerated. Fiber-optic cable usually is more expensive to use than copper cable, and the connectors are more costly and harder to assemble. Common connectors for fiber-optic networks are SC, ST, and LC. These three types of fiber-optic connectors are half-duplex, which allows data to flow in only one direction. Therefore, the two cables are needed. These are the two types of glass fiber-optic cable:
CREATING AN ETHERNET CABLE FABRICATING AN ETHERNET CROSS-OVER AND STRAIGHT-THROUGH CABLE The STRAIGHT-THROUGH ETHERNET CABLE is used in local area network to connect a PC to a network hub and router. This is the standard cable used for almost all purposes. A CROSS-OVER CABLE, on the other hand, can be used to connect two network devices directly, without the need for a router in the middle. It simply reverses some of the pins so that the output on one computer is being sent to the input of another. The following items are the materials and tools used for making Ethernet cables:
CABLE FABRICATION PROCEDURES
INTERNET PROTOCOLS Therefore, systems maintain one or more times during transmission of data. Protocols also initiate alternative actions if the network does not meet the timing rules. Many protocols consist of a suite of other protocols that are stacked in layers. These layers depend on the operation of the other layers in the suite to function properly. THE MAIN FUNCTIONS OF PROTOCOLS
TCP/IP IPX/SPX NetBEUI AppleTalk HTTP FTP SSH Telnet POP3 IMAP SMTP PROTOCOL PORTS IP Addressing A person’s name and fingerprints usually do not change. They provide a label or address for the person’s physical aspect—the body. A person’s mailing address, on the other hand, relates to where the person lives or picks up mail. This address can change. On a host, the Media Access Control (MAC) address is assigned to the host Network Interface Card (NIC) and is known as the physical address. The physical address remains the same regardless of where the host is placed on the network in the same way that fingerprints remain with someone regardless of where he or she goes. An IP address consists of a series of 32 binary bits (1s and 0s). It is very difficult for humans to read a binary IP address. For this reason, the 32 bits are grouped into four 8-bit bytes called octets. An IP address, even in this grouped format, is hard for humans to read, write, and remember. Therefore, each octet is presented as its decimal value, separated by a decimal point or period. This format is called dotted-decimal notation. When a host is configured with an IP address, it is entered as a dotted-decimal number, such as 192.168.1.5. Five Classes of IP Address The subnet mask indicates the network portion of an IP address. Like the IP address, the subnet mask is a dotted-decimal number. Usually all hosts within a LAN use the same subnet mask. Default subnet masks for usable IP addresses
IPCONFIG How to use the ipconfig command?
Assigning a STATIC IP Address
Dynamic Host Configuration Protocol (DHCP) Dynamic Host Configuration Protocol (DHCP) is a software utility used to dynamically assign IP addresses to network devices. This dynamic process eliminates the need to manually assign IP addresses. A DHCP server can be set up and the hosts can be configured to automatically obtain an IP address. When a computer is set to obtain an IP address automatically, the other entire IP addressing configuration boxes are dimmed or disabled. The server maintains a list of IP addresses to assign, and it manages the process so that every device on the network receives a unique IP address. Each address is held for a predetermined amount of time. When the time expires, the DHCP server can use this address for any computer that joins the network. These are the IP address information that a DHCP server can assign to hosts:
The DHCP server receives a request from a host. The server then selects IP address information from a set of predefined addresses that are stored in a database. After the IP address information is selected, the DHCP server offers these values to the requesting host on the network. If the host accepts the offer, the DHCP server leases the IP address for a specific period of time. Using a DHCP server simplifies the administration of a network because the software keeps track of IP addresses. Automatically configuring TCP/IP also reduces the possibility of assigning duplicate or invalid IP addresses. Before a computer on the network can take advantage of the DHCP server services, the computer must be able to identify the server on the local network. You can configure a computer to accept an IP address from a DHCP server by clicking the Obtain an IP address automatically option in the NIC configuration window. If your computer cannot communicate with the DHCP server to obtain an IP address, the Windows operating system automatically assigns a private IP address. If your computer is assigned an IP address in the range of 169.254.0.0 to 169.254.255.255, it can communicate with only other computers in the same range. An example of when these private addresses would be useful is in a classroom lab where you want to prevent access outside to your network. This operating system feature is called Automatic Private IP Addressing (APIPA). APIPA continually requests an IP address from a DHCP server for your computer. PING The ping command operates by sending Internet Control Message Protocol (ICMP) Echo Request messages to the destination computer and waiting for a response. How many of those responses are returned, and how long it takes for them to return, are the two major pieces of information that the ping command provides. PING COMMAND SYNTAX Using the PING Command
This output shows several things:
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