BASIC NETWORKING PDF
Networks are everywhere—or so it seems. You can hardly do anything with data that does not involve a network. Like the human networks that we are all part of. Describe the functionality of LAN, MAN, and WAN networks. • Identify the A network refers to two or more connected computers that . It can also perform basic. Introduction. -A network can be defined as a group of computers and other devices connected in some ways so as to be able to exchange data. -Each of the .
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“No man but a blockhead ever wrote, except for money.” - Samuel Johnson. The textbook world is changing. On the one hand, open source. Basic Networking Tutorial. 1 Compiled By Sangay Yeshi A computer network is a collection of two or more connected computers. When these computers are. What is networking? High level overview: •Making two or more computers talk to each other. •Enhancing real life interactions through networked communications.
They have been replaced by switches. If you look on Amazon for a hub it will be a switch.
The term frame is used for data units at the data link level and the the term packet for data units and the networking level. Hence we have Ethernet frames and IP packets.
The data frame contains data and frame management information. The concept used to describe data frames is that of a letter and envelope. The letter is the data which is placed inside an envelope that contains the addressing information.
This concept of data being inserted into an envelope is used repeatedly in data communications, and it is an important one to grasp.
Chapter 1: What is a Network?
The envelope containing the data letter can simply be inserted into another envelope and so on. Although the Ethernet protocol alone is sufficient to get data between two nodes on an Ethernet network, it is not used on its own. Ethernet represents what is known as a data link protocol, and for networking we need a networking protocol which in our case is IP internet protocol.
It is however the IP protocol which contains the important IP addresses, which are used for connecting computers together across the Internet, and in local networks. The diagram below illustrates how data is placed inside protocol envelopes headers. At the receiving end it is unpacked in the reverse order.
The IP address is the most important address as far as we are concerned, as it is a logical address, meaning it is assigned by us, and can be changed. Current networks use IPv4 Addresses. The IP IPv4 address is a 32 bit address and is written in dotted decimal notation and appears like this: So it is of this form: a.
When troubleshooting network problems you will need to be able to identify network addresses, and if a device has one, and whether that address is valid. If a client cannot get an IP address then some clients will auto assign an IP address.
Note: Different versions of windows use different default IP addresses In either case it is unlikely to work correctly because clients with a In our street analogy they think they are on different streets.
Finding Your IP Address To find the IP address on a windows computer using ipconfig, open a command line dos prompt and type the command ipconfig at the prompt.
The IP address here is You will also see the default gateway address This is the IP address of the Router, the term gateway is an old Unix expression that is still used. The IP address will be used to get the data packet to the final network segment. In order to deliver the packet to the final destination the MAC address of the destination computer must be known. A protocol know as ARP address resolution protocol is used, which uses an Ethernet broadcast to query the nodes on the network.
Send me your MAC address. All nodes see the query but only the node with the destination IP address replies. IP Networks Computers and other devices can be grouped together into networks. In the real world this is the same as houses are grouped together into streets. To separate devices into networks a router is required. Network numbers are part of the IP address.
Clients and Servers
So when you look at an IP address what you see is a number with two components. A network component and a node component It is the job of the Subnet mask to split the IP address into the network component and the Node component device address. For my network my computer has an IP address of To find the network address you do a logical AND of the two numbers.
Routers operate under this layer. Network topology dictates what media you must use to interconnect devices.
It also serves as basis on what materials, connector and terminations that is applicable for the setup. RIP, short for Routing Information Protocol is used by routers to send data from one network to another. It efficiently manages routing data by broadcasting its routing table to all other routers within the network.
It determines the network distance in units of hops. There are several ways to do this. Install reliable and updated anti-virus program on all computers. Make sure firewalls are setup and configured properly. User authentication will also help a lot. All of these combined would make a highly secured network. This is a peripheral card that is attached to a PC in order to connect to a network. It is an interconnection of computers and devices that are geographically dispersed.
It connects networks that are located in different regions and countries. The physical layer does the conversion from data bits to electrical signal, and vice versa. This is where network devices and cable types are considered and setup. Proxy servers primarily prevent external users who identifying the IP addresses of an internal network. Without knowledge of the correct IP address, even the physical location of the network cannot be identified.
Proxy servers can make a network virtually invisible to external users.
This layer provides the protocols and means for two devices on the network to communicate with each other by holding a session.
This includes setting up the session, managing information exchange during the session, and tear-down process upon termination of the session.
Are there limitations? A fault tolerance system ensures continuous data availability. This is done by eliminating a single point of failure. However, this type of system would not be able to protect data in some cases, such as in accidental deletions. The 10 refers to the data transfer rate, in this case is 10Mbps. The word Base refers to base band, as oppose to broad band.
T means twisted pair, which is the cable used for that network. Private IP addresses are assigned for use on intranets.
These addresses are used for internal networks and are not routable on external public networks. These ensures that no conflicts are present among internal networks while at the same time the same range of private IP addresses are reusable for multiple intranets since they do not "see" each other. NOS, or Network Operating System, is specialized software whose main task is to provide network connectivity to a computer in order for it to be able to communicate with other computers and connected devices.
DoS, or Denial-of-Service attack, is an attempt to prevent users from being able to access the internet or any other network services. Such attacks may come in different forms and are done by a group of perpetuators. One common method of doing this is to overload the system server so it cannot anymore process legitimate traffic and will be forced to reset.
It is made up of 7 layers, with each layer defining a particular aspect on how network devices connect and communicate with one another. One layer may deal with the physical media used, while another layer dictates how data is actually transmitted across the network.
The main purpose of this is to prevent crosstalk. Crosstalks are electromagnetic interferences or noise that can affect data being transmitted across cables. By using address translation instead of routing, address sharing provides an inherent security benefit. That's because host PCs on the Internet can only see the public IP address of the external interface on the computer that provides address translation and not the private IP addresses on the internal network.
It is also known as physical address or Ethernet address. A MAC address is made up of 6-byte parts.
Basic Networking Course for Beginners
If the first octet begins with a 0 bit, that address is Class A. If it begins with bits 10 then that address is a Class B address. If it begins with , then it's a Class C network. OSPF, or Open Shortest Path First, is a link-state routing protocol that uses routing tables to determine the best possible path for data exchange.
Firewalls serve to protect an internal network from external attacks. These external threats can be hackers who want to steal data or computer viruses that can wipe out data in an instant.
It also prevents other users from external networks from gaining access to the private network. This is one of the easiest to setup and maintain. Gateways provide connectivity between two or more network segments. It is usually a computer that runs the gateway software and provides translation services.A subnet mask is combined with an IP address in order to identify two parts: the extended network address and the host address.
Hubs do not create a separate collision domain they just repeat packets. These devices in networking or even called as nodes.
Full root access. To have a common language. Links and Networks Ethernet is a data link protocol. The layers in this model are: It is possible for computers to talk to each other using just Ethernet, and with no networking protocol, but it is not practical You can liken a link to a street.
The application layer is the layer that the users and user-applications most often interact with.