GAYATRI COMPUTERS Prepared by : VENKAT.G 1 What is Networking? Module 1: NETWORK BASICS Networking: Connecting two or more computers or network devices(routers/print Servers / Firewall Devices..etc) for sharing the Resources (Printer / Internet / Data / Software.etc) Figure 1.1: LAN in Star Topology What are the advantages or need of Networking? By sharing the network resources: 1.You can reduce the cost 2.You can manage / control the resources from single location 3.You can provide safety and security to the resources. What are the different types of Networks? Types of networks depend upon way of geographical area and connections: 1.LAN -Local Area Network 2.WAN-Wide Area Network 3.MAN -Metropolitan Area Network 4.SAN - Storage Area Network, System Area Network, Server Area Network, or sometimes Small Area Network 5. WLAN - Wireless Local Area Network 6. CAN - Campus Area Network But mainly networks are classified as two types 1. LAN and 2.WAN
GAYATRI COMPUTERS Prepared by : VENKAT.G 2 What is LAN (Local Area Network)? LAN (Local Area Network) : Connecting two or more computers or network devices within a single room / building by using physical media / wireless access devices (WLAN Cards) is called as LAN. (Refer Figure 1.1) What is WAN (Wide Area Network)? WAN (Wide Area Network) : Connecting two or more computers or LANs which are located at different geographical long distance places by using remote medias called as WAN 1.Dialup Connection / RAS (Remote Access Service) : Connecting two LANs or Computers through telephone line and Modem and accessing network resources from remote computer. But this is low speed connection :64Kbps and it is more expensive.
GAYATRI COMPUTERS Prepared by : VENKAT.G 3 What is an ISDN / T1 Leased Line? 1.ISDN stands for Integrated Services Digital Network. 2.In ISDN line simultaneously you can communicate (send / receive) data and Voice. 3.It is high speed dedicated connection between client and teclo / ISP. 4.It is more expensive Figure 1.4 : WAN connection by using ISDN Line and ISDN Modem / Router What is Frame Relay? 1. Frame Relay is a virtual circuit based packet-switching technology that permits WAN implementations of up to speeds (44.7 Mbps). 2.Most implementations of Frame Relay use permanent virtual circuits (PVCs). What are the requirements for implementing LAN? Requirements for implementing LAN: Server Clients Network Devices / Equipments (Network Adapters,Repeaters,Bridges, Hubs, Switches, Routers) Cables. Selecting of Network Topology Selecting of Network Protocols Selecting of Network Models (Workgroup Model or Domain Model ) Selecting of O.S Server : The computer(s) or Network Devices ( Routers / Firewall / Print manager / IP Camera etc) which can supply the network resources to the clients depend upon permissions /rights.
GAYATRI COMPUTERS Prepared by : VENKAT.G 4 Client : The Computers / network devices which can use the resources from server. The client request to server,server checks the permissions and supply the resources to the clients. Network Adapter / LAN Card / Ethernet Controller / NIC : It is an I/O (Input / Output ) used for every computer to communicate (send / receive) data from one computer to other computers in a network. What is MAC Address? Every LAN card has unique identification address called as MAC (Media Access Control) address. MAC Address is 12 bit number like 00-1F-29-80-B8-C3 Specifications / Features of Network Adapters / LAN Card: 1. Speed : In computers data communicated in the form of zeros and ones (0 AND 1).Speed of the network measured in the form of bps (bits per second) Figure 1.5: Measurement Units and LAN card speeds 2.Duplex Mode /Type of Communication : Network Adapter communicate data in two ways. 1.Half Duplex : Simultaneously both sending and receiving is not possible Full Duplex : Simultaneously both sending and receiving is possible Figure 1.6: Half-Duplex Mode and Full-Duplex Mode
GAYATRI COMPUTERS Prepared by : VENKAT.G 5 Figure 1.7: LAN card with different cables and connectors Figure 1.8: Different types of Ethernet / LAN cards What is CSMA / CD? Ethernet networking uses Carrier Sense Multiple Access With Collision Detection (CSMA/CD).A protocol that helps devices share the bandwidth evenly without having two devices transmit at the same time on the network medium. When the collision occurs on the Ethernet LAN? A jam signal informs all devices that a collision occurred. The collision invokes a random backoff algorithm. Each device on the Ethernet segment stops Transmitting for a short time until the Times Expire. All hosts have equal priority to transmit after the timers expired.
GAYATRI COMPUTERS Prepared by : VENKAT.G 6 What is a Repeater? A repeater is an OSI model layer-1 hardware component that transmits frames from one wire and places them on another. Repeaters are a simple way to extend a LAN segment. What is a Bridge? A bridge is an OSI model layer-2 hardware component that is used to connect multiple segments. Bridges use MAC addresses to handle traffic flow A bridge can also filter by MAC address The bridging cache maintains a MAC address table, similar to an ARP cache, but includes a database of which interface on the bridge the MAC address resides on. This table is crucial for the filtering software. If an Ethernet frame contains a source MAC address (SA) and a destination MAC address (DA) from a network segment on the same interface, then the frame is not forwarded to the rest of the network. The bridging software can make this distinction by using the MAC address and interface lookup table.
GAYATRI COMPUTERS Prepared by : VENKAT.G 7 What is a Hub? Hub is a multi port repeater. Hubs joins group of multiple computers together. Hub is Broadcast device. In the hub equal bandwidth is not shared to all computers. Data Collision is more. Figure 1.11 :Hub What is a Switch? Switch is similar to Hub but Switch uses MAC address to handle traffic flow and filtering Process. Switch is like a multi port Bridge. Switch is Unicast device switches provide dedicated bandwidth with very little window for collisions to take place due to their point-to-point nature. The switch software can make this distinction by using the MAC address and interface lookup table. Figure 1.12 :Switch What is Unicasting, Multicasting and Broadcasting? Unicast - A unicast is a transmission from one node addressed specifically to another node. Multicast - In a multicast, a node sends a packet addressed to a special group address. Devices that are interested in this group register to receive packets addressed to the group. An example might be a Cisco router sending out an update to all of the other Cisco routers. Broadcast - In a broadcast, a node sends out a packet that is intended for transmission to all other nodes on the network.
GAYATRI COMPUTERS Prepared by : VENKAT.G 8 What are the differences between Hub and Switch? Hub 1.Hub is Broad cast device 2.Equal Bandwidth is not shared 3.It will not use MAC address and Lookup table for communicating data 4.In Hub collision is more Switch 1.Switch is unicast device 2.Equal Bandwidth is shared 3.It will use MAC address and Lookup table for communicating and Filtering data 4.In switch collision is less What is a Router? Router is a gateway device which is used to show the route between two or more networks. Router uses the routing table to forward the data packets from one network to other networks. Figure 1.13 :Router connecting between two different networks Figure 1.14 :Cisco Router
GAYATRI COMPUTERS Prepared by : VENKAT.G 9 Types of Cables (OR) Physical Medias : To carry the information from one device to other device,you require a media (cable) Types of cables : 1.Co-axial Cable 2.UTP (Unshielded Twisted Pair ) cable 3.STP (Shielded Twisted Pair) Cable 4.Fiber Optic Cable 1.Co-axial cable Features : Coaxial cabling has a single copper conductor at its center. A plastic layer provides insulation between the center conductor and a braided metal shield. The metal shield helps to block any outside interference. It can support greater cable lengths between network devices than twisted pair cable Figure 1.14 : Co-axial cable and connectors used for Co-axial cable Types of Co-axial cables: 1.Thin Co-axial cable / Thinnet : 10Base2 refers to the specifications for thin coaxial cable carrying Ethernet signals. The 2 refers to the approximate maximum segment length being 200 meters. 2. Thick coaxial cable /Thicknet : 10Base5 refers to the specifications for thick coaxial cable carrying Ethernet signals. The 5 refers to the maximum segment length being 500 meters.
GAYATRI COMPUTERS Prepared by : VENKAT.G 10 2.UTP (Unshielded Twisted Pair) cable Features : U Unshielded (There is no shielding wire ) T Twisted (The cables in twisted format) P Pair (Pair means two ) Figure 1.15 :UTP cable and RJ 45 connector UTP (Unshielded Twisted Pair) cable categories :
GAYATRI COMPUTERS Prepared by : VENKAT.G 11 Why STP Cable is required? or What are differences between UTP and STP Cables? Although UTP cable is the least expensive cable, it may be susceptible to radio and electrical frequency interference (it should not be too close to electric motors, fluorescent lights, etc.). If you must place cable in environments with lots of potential interference, or if you must place cable in extremely sensitive environments that may be susceptible to the electrical current in the UTP, shielded twisted pair may be the solution. Shielded cables can also help to extend the maximum distance of the cables. Shielded twisted pair cable is available in three different configurations: Each pair of wires is individually shielded with foil. There is a foil or braid shield inside the jacket covering all wires (as a group). There is a shield around each individual pair, as well as around the entire group of wires (referred to as double shield twisted pair). Figure 1.16: STP (Shielded Twisted Pair) cable 3. Fiber Optic cable features: Fiber optic cabling consists of a center glass core surrounded by several layers of protective materials It transmits light rather than electronic signals Fiber optic cable has the ability to transmit signals over much longer distances than coaxial and twisted pair It also has the capability to carry information at vastly greater speeds It is used for video conferencing and interactive services. It is more expensive compared to other cables Figure 1.17 :Fiber Optic cable and Jack
GAYATRI COMPUTERS Prepared by : VENKAT.G 12 What is Network Topology? Topology: The Physical way of connecting all computers or network devices in a network is called as Topology. (OR) The layout of the Network is called as Topology. Types of Topologies: Types of Topologies : Depend upon number of computers / network devices and placing of computers / network devices in an organization,the topologies are classified as 1.Bus Topology 2.Star Topology 3.Ring (Token Ring) Topology 4.Hybrid Topology 3.Tree Topology 4.Mesh Topology. 1.Bus Topology One computer end is connected other computer like serial. Advantages of Bus Topology : 1.It is less cost because less cable length is required. 2.It is very easy to implement. Disadvantages of Bus Topology : 1.If any one of the cable disconnected at any computer,then the entire network will be down. 2.Troubleshooting is difficult to find out where the cable disconnected. Figure 1.18 :Bus Topology
GAYATRI COMPUTERS Prepared by : VENKAT.G 13 2. Star Topology A star topology is designed with each node (file server, workstations, and peripherals) connected directly to a central network hub Advantages of Star Topology : 1.Speed is more compared more because Hub / Switch amplify the signal and distributes signals 2.If any one of the cable may disconnected / damaged only that computer will be out from the network, it is not effecting the entire network 3.Troubleshooting is easy. Disadvantages of Star Topology: 1.It is expensive compared to Bus Topology because it require special device called as Hub / Switch and it require more Cable length 2. If the Hub / Switch failure then entire network may be down 3. It is suitable for small network, if all the computers located in a single room Figure 1.19 :Star Topology 3. Ring / Token Ring Topology Stations on a token ring LAN are logically organized in a ring topology with data being transmitted sequentially from one ring station to the next with a control token circulating around the ring controlling access. IBM popularized the use of token ring LANs in the mid 1980s when it released its IBM token ring architecture based on active multi-station access units (MSAUs or MAUs) and the IBM Structured Cabling System A data token ring frame is an expanded version of the token frame that is used by stations to transmit media access control (MAC) management frames or data frames from upper layer protocols and applications.
GAYATRI COMPUTERS Prepared by : VENKAT.G 14 Figure 1.20 :Token Ring Topology Figure 1.21 :MAU (Multi-station Access Unit) used in Token Ring Topology 4. Hybrid Topology The combination of Star and bus or Star and Ring topology is called as Hybrid. If the computers / network devices located in different rooms / buildings. Figure 1.22: Hybrid Topology
GAYATRI COMPUTERS Prepared by : VENKAT.G 15 5. Tree Topology In this topology all department s hubs / switches connected to one main root Hub / Switch It is suitable for big network, where all departments are located at different rooms / buildings. This Topology is helping to manage the entire network from single location (from server Room ) Figure 1.20 :Tree Topology
GAYATRI COMPUTERS Prepared by : VENKAT.G 16 Crimping / Cabling: Connecting / Inserting UTP cable in RJ45 connector is called as crimping. There are two types of crimping / cables 1. Strigh cable: It is used for connecting between Hub to PC or Switch to PC 2. Cross cable: It is used for connecting between similar devices like o PC to PC o Hub to Hub o Switch to Switch Figure 1.21: Straight Cable Figure 1.22: Cross Over Cable
GAYATRI COMPUTERS Prepared by : VENKAT.G 17 Figure 1.23: Crimping Tool Figure 1.24: LAN Cable Tester Network Protocols: What is a Protocol? A protocol is a language your computer uses to communicate with other computers in a network. (OR) The set of rules and regulations to communicate data from one computer to other computers.
GAYATRI COMPUTERS Prepared by : VENKAT.G 18 Types of Network Protocols : 1.Routable Protocols 2.Non Routing Protocols 3.Routing Protocols 1. Routable Protocols: A communications protocol that contains a network address as well as a device address. It allows packets to be forwarded from one network to another. Examples of routable protocols are TCP/IP, IPX/SPX, AppleTalk TCP/IP- Transmission Control Protocol / Internet Protocol IPX/SPX-Intranet Packet Exchange / Sequential Packet Exchange 2. Non Routable Protocols: A communications protocol that contains only a device address and not a network address. It does not incorporate an addressing scheme for sending data from one network to another. Examples of non-routable protocols are NetBEUI NetBIOS-Network Basic Input Output Extended User Interface. 3. Routing Protocols: A formula used by routers to determine the appropriate path onto which data should be forwarded. The routing protocol also specifies how routers report changes and share information with the other routers in the network that they can reach. A routing protocol allows the network to dynamically adjust to changing conditions Examples of Routing Protocols: RIP, OSPF, IGRP, EGP and BGP. RIP Routing Information Protocol OSPF Open Shortest Path First IGRP Interior Gateway Routing Protocol EGP Exterior Gateway Protocol BGP Border Gateway Protocol What is TCP / IP? TCP / IP (Transmission Control Protocol / Internet Protocol ) TCP / IP is the standard protocol for LAN,WAN and Internet. TCP / IP is supported by all family of O.Ss TCP / IP is the combination of two protocols 1. TCP (Transmission Control Protocol ) 2. IP (Internet Protocol )
GAYATRI COMPUTERS Prepared by : VENKAT.G 19 What are the functions of TCP / IP? Functions of IP: IP will find out Source and Destination Host IP Addresses. IP will create logical link between source and Destination Host. FROM Address (where ) Source to TO Address (to where) Destination path will be created by IP. Functions o f TCP: TCP will transfer (send /receive) data packets between source and destination hosts. TCP will perform data sequencing job TCP will perform data flow control. TCP will perform error checking. What is an IP Address? IP Address is an unique identification address of a computer / host in the network, by using these address one computer finds other computers in an network and makes data communications between the computers. IP Address Format: IP Address is a 32 bit binary address.this 32 bit binary IP address divided into four bytes (one byte = 8bits ) NOTE : if the IP Address is in the form of binary format, it is very difficult to remember and to configure the IP address.for easy configuration of IP Address,you are using Decimal format (192.168.120.130) Number Systems : Binary Number system : Bi means two ( 0 and 1) Decimal Number System : Deci means ten ( 0 to 9)
GAYATRI COMPUTERS Prepared by : VENKAT.G 20 How to convert from Binary number (10101010) to Decimal Number? How to convert from Decimal to Binary number?
GAYATRI COMPUTERS Prepared by : VENKAT.G 21 Range of IP Address in Decimal format: Classes of IP Address: IP Address divided into five classes depends upon the size of the network. Class A IP Address Class B IP Address Class C IP Address Class D IP Address Class E IP Address How to find out IP address Class according to Priority bit?
GAYATRI COMPUTERS Prepared by : VENKAT.G 22 Class A IP Address Range: For Class A range reserved first bit in first octet, the value of that bit should not change. Class B IP Address Range: For Class B range reserved first two bit in first octet, the value of that bit should not change.
GAYATRI COMPUTERS Prepared by : VENKAT.G 23 Class C IP Address Range: For Class C range reserved first three bit in first octet, the value of that bit should not change. Class D IP Address Range: For Class D range reserved first four bit in first octet, the value of that bit should not change.
GAYATRI COMPUTERS Prepared by : VENKAT.G 24 Class E IP Address Range: For Class E range reserved first four bit in first octet, the value of that bit should not change. Structure / Portions of IP Address: IP address is divided into Network & Host Portion CLASS A is written as: N.H.H.H CLASS B is written as : N.N.H.H CLASS C is written as : N.N.N.H Number of Networks and Number of Hosts per network in Class A : Class A IP Address Format is N.H.H.H Network bits : 8 and Host bits : 24 Number of Networks = 2 8-1 (-1 is Priority Bit for Class A) = 2 7 = 128 2 (-2 is for 0 & 127 Network) = 126 Networks Number of Hosts per Network = 2 24 2 (-2 is for Network ID & Broadcast ID) = 16777216-2 = 16777214 Hosts/Network Default Subnet Mask :255.0.0.0
GAYATRI COMPUTERS Prepared by : VENKAT.G 25 Number of Networks and Number of Hosts per network in Class B : Class B IP Address Format is N.N.H.H Network bits : 16 Host bits : 16 Number of Networks = 2 16-2 (-2 is Priority Bit for Class B) = 2 14 = 16384 Networks Number of Hosts per Network = 2 16 2 (-2 is for Network ID & Broadcast ID) = 65536-2 = 65534 Hosts/Network Default Subnet Mask :255.255.0.0 Number of Networks and Number of Hosts per network in Class C : Class C Octet Format is N.N.N.H Network bits : 24 Host bits : 8 No. of Networks = 2 24-3 (-3 is Priority Bit for Class C) = 2 21 = 2097152 Networks Number of Hosts per Network = 2 8 2 (-2 is for Network ID & Broadcast ID) = 256-2 = 254 Hosts/Network Default Subnet Mask: 255.255.255.0
GAYATRI COMPUTERS Prepared by : VENKAT.G 26 Example - Class A IP Address : Class A : N.H.H.H Network Address: 0xxxxxxx.00000000.00000000.00000000 Broadcast Address: 0xxxxxxx.11111111.11111111.11111111 Class A 10.0.0.0 10.0.0.1 10.0.0.2 10.0.0.3 10.255.255.254 10.255.255.255 What is Subnet mask? Subnet Mask differentiates Network portion and Host Portion Subnet Mask is been given for host Identification of Network ID Represent all Network Bit Values with 1 Represent all Host Bit Values with 0 Class A : N.H.H.H 11111111.00000000.00000000.00000000 Default Subnet Mask for Class A is 255.0.0.0 Class B : N.N.H.H 11111111.11111111.00000000.00000000 Default Subnet Mask for Class B is 255.255.0.0 Class C : N.N.N.H 11111111.11111111.11111111.00000000 Default Subnet Mask for Class C is 255.255.255.0 Ranges, Number of Networks and Number of Hosts per Network in Class A,B and C
GAYATRI COMPUTERS Prepared by : VENKAT.G 27 What is Private IP Address and why do you require Private IP address? In Multi National Organizations, users / employees have to access there servers from different locations in the word wide,so those servers must require Static Public IP Addresses to access from Public. Because of insufficient of Public IP Addresses and Expensive of Public IP Addresses,so IANA designed Private IP Address. What are Private IP addresses (OR) Non-Routable IP Addresses? The Internet Assigned Numbers Authority (IANA) has reserved the following three blocks of the IP address space for private internets (local networks) Note :IP addresses in the range of 169.254.0.0-169.254.255.255 are reserved for Automatic Private IP Addressing(APIPA) supported by Microsoft Family What are the differences between Public IP Address and Private IP Address? Public IP Address 1.These are Routable IP Addresses 2.By using these IP Addresses,you can directly connected to Internet (Public Network) 3.You have to buy these IP Addresses 4.These are used for Public Servers, those we can access from outside (Public) Private IP Address 1.These are not Routable IP Addresses 2.By using these IP Addresses,you can not connect to Internet (Public),You have connect to Internet through NAT / Proxy Server 3.These IP Addresses are Free 4.These are used for LAN with in Organization
GAYATRI COMPUTERS Prepared by : VENKAT.G 28 Introduction of IP v6 (version6): IP V6 is 128bit address 128-bit address is divided along 16-bit boundaries. Each 16-bit block is converted to a 4-digit hexadecimal number and separated by colons (Colon-Hex Notation) Example: FEDC: BA98:7654:3210: FEDC: BA98:7654:3210 What is an Operating System (O.S)? Operating System is an Interface between user and Hardware Devices (OR) Operating System is the core software which controls both Hardware devices and Applications Software. Types of Operating Systems : Desktop Operating System : An Operating System which controls Hardware devices and applications software in single computer (in that computer only).it is also called as Single User O.S Network Operating System: An Operating System which controls hardware devices and applications software in all computers in that Network is called as Network O.S / Multi user O.S.
GAYATRI COMPUTERS Prepared by : VENKAT.G 29 List of Microsoft family O.S :