CCNA – CHAPTER 01
INTRODUCTION TO NETWORKING
, Introduction to Networking
Basics of Networking
❖ What is a network anyway?
A network is just a collection of devices and end systems connected to each other and able to
communicate with each other. These could be computers, servers, smartphones, routers etc. A
network could be as large as the internet or as small as your two computers at home sharing
files and a printer.
Some of the components that make up a network:
• Personal Computers (PC): These are the endpoint of your network, sending and receiving data.
• Interconnections: These are components that make sure data can travel from one device to
another, you need to think about:
o Network Cards: they translate data from your computer in a readable format for the
network.
o Media: network cables, perhaps wireless.
o Connectors: the plug you plug in your network card.
• Switches: These boxes are network devices which provide a network connection for your end
devices like PC‟s.
• Routers: Routers interconnect networks and choose the best path to each network destination.
If you are going to work with Cisco, you’ll have to get used to some network diagrams like the one below:
First of all, we see a computer connected to a switch. On the switch side you see “Fa0/1” which means
the computer is connected to the FastEthernet 0/1 interface on the switch side. The 0 is the controller
number (usually 0 on smaller switches) and the 1 is the port number. Our switch is connected to a router
using its FastEthernet 0/24 interface. Our routers are connected using FastEthernet as well. The router
at the bottom has a connection to the Internet using a Serial connection.
, So why do we use networks? I think this one is obvious since you are using networks on a daily basis but
let’s sum up what we use networks for:
• Applications: Sending data between computers, sharing files.
Resources: Network printers, network cameras.
• Storage: Using a NAS (Network attached storage) will make your storage available on the network.
Many people use one at home nowadays to share files, videos and pictures between computers.
• Backup: Using a central backup server where all computers send their data to for backup.
• VoIP: Voice over IP is becoming more important and every day and replacing analog telephony.
When we look at networks, we have different types of “Topologies”, and we have two different topologies:
• • Physical topology
• • Logical topology
There’s an important difference between the two. The physical topology is what the network looks like and how all
the cables and devices are connected to each other. The logical topology is the path our data signals take through
the physical topology.
There are multiple types of physical topologies:
Network Topologies
Bus Topology
Bus topology is a network type in which every computer and network device is connected to single cable.
When it has exactly two endpoints, then it is called Linear Bus topology.
Features of Bus Topology
• • It transmits data only in one direction.
• • Every device is connected to a single cable
Advantages of Bus Topology
• • It is cost effective.
• • Cable required is least compared to other network topology.
• • Used in small networks.
• • It is easy to understand.
• • Easy to expand joining two cables together.
INTRODUCTION TO NETWORKING
, Introduction to Networking
Basics of Networking
❖ What is a network anyway?
A network is just a collection of devices and end systems connected to each other and able to
communicate with each other. These could be computers, servers, smartphones, routers etc. A
network could be as large as the internet or as small as your two computers at home sharing
files and a printer.
Some of the components that make up a network:
• Personal Computers (PC): These are the endpoint of your network, sending and receiving data.
• Interconnections: These are components that make sure data can travel from one device to
another, you need to think about:
o Network Cards: they translate data from your computer in a readable format for the
network.
o Media: network cables, perhaps wireless.
o Connectors: the plug you plug in your network card.
• Switches: These boxes are network devices which provide a network connection for your end
devices like PC‟s.
• Routers: Routers interconnect networks and choose the best path to each network destination.
If you are going to work with Cisco, you’ll have to get used to some network diagrams like the one below:
First of all, we see a computer connected to a switch. On the switch side you see “Fa0/1” which means
the computer is connected to the FastEthernet 0/1 interface on the switch side. The 0 is the controller
number (usually 0 on smaller switches) and the 1 is the port number. Our switch is connected to a router
using its FastEthernet 0/24 interface. Our routers are connected using FastEthernet as well. The router
at the bottom has a connection to the Internet using a Serial connection.
, So why do we use networks? I think this one is obvious since you are using networks on a daily basis but
let’s sum up what we use networks for:
• Applications: Sending data between computers, sharing files.
Resources: Network printers, network cameras.
• Storage: Using a NAS (Network attached storage) will make your storage available on the network.
Many people use one at home nowadays to share files, videos and pictures between computers.
• Backup: Using a central backup server where all computers send their data to for backup.
• VoIP: Voice over IP is becoming more important and every day and replacing analog telephony.
When we look at networks, we have different types of “Topologies”, and we have two different topologies:
• • Physical topology
• • Logical topology
There’s an important difference between the two. The physical topology is what the network looks like and how all
the cables and devices are connected to each other. The logical topology is the path our data signals take through
the physical topology.
There are multiple types of physical topologies:
Network Topologies
Bus Topology
Bus topology is a network type in which every computer and network device is connected to single cable.
When it has exactly two endpoints, then it is called Linear Bus topology.
Features of Bus Topology
• • It transmits data only in one direction.
• • Every device is connected to a single cable
Advantages of Bus Topology
• • It is cost effective.
• • Cable required is least compared to other network topology.
• • Used in small networks.
• • It is easy to understand.
• • Easy to expand joining two cables together.
