Achievable CCNA

1. Introduction to networking

Our CCNA course is currently in development and is a work-in-progress.

How devices communicate on a TCP/IP based network

2 min read

Imagine you’re on your phone or computer and you open a social media app. You see a video your friend posted from what everyone called the biggest concert of the year. Under the video are comments from mutual friends - and from people you’ve never met, from all over the world.

Sharing photos, videos, and thoughts online is so common that it’s easy to forget what’s happening behind the scenes. A useful question to ask is this:

How can someone take a photo on their phone and upload it into a space where people anywhere in the world can view it, comment on it, and discuss it - even if they aren’t in the same place at the same time?

Not long ago, people asked the same kind of question about email:

How can you type a message and have someone receive it almost instantly?
How does that message travel from your phone or computer to the recipient’s device, even if they’re across the globe?

You can ask the same question about what you’re doing right now: how are you able to access and view the content in this course?

The answer to all of these questions is computer networking. Networking is the set of technologies and rules (called protocols) that let devices and applications exchange data - messages, files, pictures, and videos - over a network.

These technologies and protocols work together underneath the apps you use every day. And the largest network most people use is the Internet.

The Internet is a massive public network made up of interconnected devices such as routers, switches, and servers. When your phone, computer, or a server is connected to the Internet, applications on those devices can send and receive data with other connected devices.

Here’s a practical way to think about it: when you browse the web, you’re viewing content that lives on a web server connected to the Internet. Because that server is online, anyone else connected to the Internet can request and view the same content.

Now that we’ve identified what makes this possible, the next page focuses on how it works.

Computer Networking

Enables data exchange between devices and applications
Uses technologies and protocols (rules for communication)
Supports messages, files, photos, videos sharing

Protocols

Define how devices communicate and exchange data
Essential for reliable and standardized networking

The Internet

Largest public network of interconnected devices
Includes routers, switches, servers
Allows global data access and sharing

Web Servers

Store and deliver web content to users
Accessible by any device connected to the Internet

Everyday Applications

Social media, email, and online courses rely on networking
Data travels instantly across global networks

Next | 1.4 The layers of the TCP/IP model

How devices communicate on a TCP/IP based network

Sharing photos, videos, and thoughts online is so common that it’s easy to forget what’s happening behind the scenes. A useful question to ask is this:

Not long ago, people asked the same kind of question about email:

How can you type a message and have someone receive it almost instantly?
How does that message travel from your phone or computer to the recipient’s device, even if they’re across the globe?

You can ask the same question about what you’re doing right now: how are you able to access and view the content in this course?

These technologies and protocols work together underneath the apps you use every day. And the largest network most people use is the Internet.

Now that we’ve identified what makes this possible, the next page focuses on how it works.

Key points

Computer Networking

Enables data exchange between devices and applications
Uses technologies and protocols (rules for communication)
Supports messages, files, photos, videos sharing

Protocols

Define how devices communicate and exchange data
Essential for reliable and standardized networking

The Internet

Largest public network of interconnected devices
Includes routers, switches, servers
Allows global data access and sharing

Web Servers

Store and deliver web content to users
Accessible by any device connected to the Internet

Everyday Applications

Social media, email, and online courses rely on networking
Data travels instantly across global networks

How devices communicate on a TCP/IP based network

Sharing photos, videos, and thoughts online is so common that it’s easy to forget what’s happening behind the scenes. A useful question to ask is this:

Not long ago, people asked the same kind of question about email:

How can you type a message and have someone receive it almost instantly?
How does that message travel from your phone or computer to the recipient’s device, even if they’re across the globe?

You can ask the same question about what you’re doing right now: how are you able to access and view the content in this course?

These technologies and protocols work together underneath the apps you use every day. And the largest network most people use is the Internet.

Now that we’ve identified what makes this possible, the next page focuses on how it works.

Computer Networking

Enables data exchange between devices and applications
Uses technologies and protocols (rules for communication)
Supports messages, files, photos, videos sharing

Protocols

Define how devices communicate and exchange data
Essential for reliable and standardized networking

The Internet

Largest public network of interconnected devices
Includes routers, switches, servers
Allows global data access and sharing

Web Servers

Store and deliver web content to users
Accessible by any device connected to the Internet

Everyday Applications

Social media, email, and online courses rely on networking
Data travels instantly across global networks

How devices communicate on a TCP/IP based network

Sharing photos, videos, and thoughts online is so common that it’s easy to forget what’s happening behind the scenes. A useful question to ask is this:

Not long ago, people asked the same kind of question about email:

How can you type a message and have someone receive it almost instantly?
How does that message travel from your phone or computer to the recipient’s device, even if they’re across the globe?

You can ask the same question about what you’re doing right now: how are you able to access and view the content in this course?

These technologies and protocols work together underneath the apps you use every day. And the largest network most people use is the Internet.

Now that we’ve identified what makes this possible, the next page focuses on how it works.

Key points

Computer Networking

Enables data exchange between devices and applications
Uses technologies and protocols (rules for communication)
Supports messages, files, photos, videos sharing

Protocols

Define how devices communicate and exchange data
Essential for reliable and standardized networking

The Internet

Largest public network of interconnected devices
Includes routers, switches, servers
Allows global data access and sharing

Web Servers

Store and deliver web content to users
Accessible by any device connected to the Internet

Everyday Applications

Social media, email, and online courses rely on networking
Data travels instantly across global networks