Network Concepts

Outlines What is Network ? Types of Networks Network Topologies Some of Network Devices and cables What is protocol CCNA

What is Network ? Computer network : A collection of computing devices that are connected in various ways in order to communicate and share resources . Usually, the connections between computers in a network are made using physical wires or cables However, some connections are wireless, using radio waves or infrared signals . The generic term node or host refers to any device on a network

What is Network ? cont…. Gateway Servers Firewall Switches Clients

Types of Networks Local Area Network (LAN) Wide Area Network (WAN)

Types of Networks cont… Local Area Network (LAN) : A network that connects a relatively small number of machines in a relatively close geographical area Wide Area Network (WAN) : A network that connects two or more local-area networks over a potentially large geographic distance

LAN Network Topologies Bus Topology Star Topology Ring Topology

LAN Network Topologies cont… Bus Topology: All nodes are connected to a single communication line that carries messages in both directions CSMA/CD : Carrier Sense Multi Access / Collation Detection Disadvantages : Adding more computers will reduce the access speed on the network. Collations Terminator

LAN Network Topologies cont… Ring Topology: A configuration that connects all nodes in a closed loop on which messages travel in one direction Token : In this topology, to transmit on the wire your computer must have control of the token or wait for the token to be free Disadvantages : that a single malfunctioning workstation can disable the whole network

LAN Network Topologies cont… Star Topology: A configuration that centers around one node to which all others are connected and through which all messages are sent Disadvantages : Expensive if a central device was to fail then all computers connected to that device would not be able to see the network

Network Devices

Network Devices What is a Hub? A hub is usually a small rectangular box, often made of plastic, which receives its power from an ordinary wall outlet A hub joins multiple computers (or other network devices) together to form a single network segment On this network segment, all computers can communicate directly with each other Larger hubs contain 8, 12, 16, and even 24 ports Many times the last port is reserved for "uplink" which is the connecting of one hub to another hub or similar device (joining two segments together).

Network Devices cont…. What is a Hub? a packet: types of hubs : Essentially, a hub simply receives incoming packets, possibly amplifies the electrical signal, and broadcasts these packets out to all devices on the network - including the one that originally sent the packet! a packet: is a formatted block of data carried by a computer network types of hubs : Passive : do not amplify the electrical signal of incoming packets Active : amplify the electrical signal of incoming packets back to their original level Intelligent: is typically stackable (built in such a way that multiple units can be placed one on top of the other to conserve space).

Network Devices cont…. What is a Network Switch? A network switch is a small hardware device that joins multiple computers together within one local area network (LAN) Unlike hubs, network switches are capable of inspecting data packets as they are received, determining the source and destination device of that packet, and forwarding it appropriately By delivering each message only to the connected device it was intended for, a network switch conserves network bandwidth and offers generally better performance than a hub

Network Devices cont…. What is a Router? A Gateway: Routers are physical devices that join multiple wired or wireless LAN networks together Technically, a wired or wireless router is a Layer 3 gateway device A Gateway: is a device that acts like a security guard and only allows data in or out if it has the right network headers

Network Cables

What is protocol Protocols: are the rules governing the transfer of data information, it can also be compared to how humans use languages (to get your point across you must talk in the same language as the person you are speaking to). Home “networkers” often use an Internet Protocol (IP) wired or wireless for communication

Cisco Certified Network Associate

CCNA Certification Adaptive Testing 1 Paper : 150 US $ Course Information CCNA Certification Adaptive Testing 1 Paper : 150 US $ Time Limit : 90 minutes No. Questions : 55 – 65 Passing Score : 849/1000 Questions Format : Single Choice Multiple Choice Drag & Drop Fill in the Blanks Router Simulations Scenario Based

CCNA Routing and Switching Study Guide by Todd Lammle Reference Books Reference Books CCNA Routing and Switching Study Guide by Todd Lammle

CCNA Course Overview Day 1 : OSI Layers Day 2 : IP Addressing & Subnetting Day 3 : Subnetting, VLSM & CIDR Day 4 : Initial Configuration & Internal & External of Routers Day 5 : Wan Interface Configuration & Static & Default Routing Day 6 : Dynamic Routing : RIP & IGRP Day 7 : Dynamic Routing : OSPF & EIGRP Day 8 : Access List - Standard, Extended & Named Day 9 : Switching Day 10 : VLAN – Virtual Lan Day 11 : Integrated Service Digital Network Day 12 : Frame- Relay Day 13 : Troubleshooting of Leased Line

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