NAT Explained - Network Address Translation

Summary

Network Address Translation (NAT) is a crucial service in routers that conserves the limited supply of IPv4 public addresses by translating private IP addresses for multiple devices to a single public IP. Created in response to the unforeseen growth of the internet, NAT allows for efficient internet access without the need for each device to have its own public IP address. As we transition to IPv6, which can provide a public IP for every device on Earth, the need for NAT and private IPs will diminish, thanks to its capability to generate over 340 undecillion unique addresses, ensuring no shortage in the future.

Takeaways

• 🌐 NAT stands for Network Address Translation, a service used in routers to manage IP addresses.
• 🔄 The purpose of NAT is to translate a set of IP addresses, typically from private to public, to conserve IP address space.
• 🚀 The creation of NAT was prompted by the realization that the initial 4 billion IPv4 addresses would not be sufficient for the growing internet.
• 📊 IPv4 addresses are divided into public and private types, with public addresses required for internet access and private addresses used internally.
• 🏢 Private IP addresses are not registered on the internet and cannot be used to directly access the internet; they are assigned by routers within a local network.
• 🔑 Routers assign private IP addresses to devices within a home or business, conserving the need for more public IP addresses from ISPs.
• 💡 NAT allows multiple devices with private IP addresses to share a single public IP address for internet access, reducing the demand for public IP addresses.
• 🔄 NAT not only translates private IP addresses to public but also vice versa, enabling communication between the internet and devices on a private network.
• 🌐 The future of IP addressing is IPv6, which can provide a public IP address for every device on earth, eliminating the need for NAT and private IP addresses.
• 🔢 IPv6 is capable of generating an astronomical number of IP addresses, specifically over 340 undecillion, ensuring that there will never be a shortage.
• 📈 With the advent of IPv6, the limitations of IPv4 and the need for NAT will be overcome, allowing for a more expansive and efficient internet infrastructure.

Q & A

What does NAT stand for and what is its primary function?

NAT stands for Network Address Translation. Its primary function is to translate a set of IP addresses to another set, allowing for the conservation of the limited number of IPv4 public IP addresses available globally.

Why was NAT developed?

NAT was developed to prevent a shortage of public IPv4 addresses. When the Internet expanded beyond the expectations of its creators, the initially available 4 billion IPv4 addresses were not sufficient, leading to the creation of private IP addresses and NAT.

What is the difference between public and private IPv4 addresses?

Public IPv4 addresses are registered on the Internet and are necessary for devices to access the Internet. Private IPv4 addresses, on the other hand, are not publicly registered and cannot be used to directly access the Internet. They are used internally within a home or business network.

How many public IPv4 addresses are available, and why are they considered limited?

There are approximately 4 billion public IPv4 addresses available, which are considered limited due to the vast number of devices requiring Internet access. This limitation necessitates the use of NAT to conserve these addresses.

Why is it impractical to assign a public IP address to every device that needs Internet access?

Assigning a public IP address to every device would be expensive, unnecessary, and a waste of public IP addresses. It would also deplete the available public IPv4 addresses much faster, leading to a shortage.

How does a router assign IP addresses to devices within a home or business network?

A router assigns private IP addresses to devices within a home or business network. When these devices need to access the Internet, their private IP addresses are translated by NAT to the public IP address provided by the Internet Service Provider.

What is the role of NAT when a device with a private IP address needs to access the Internet?

NAT translates the private IP address of a device to a public IP address, allowing it to access the Internet. This process conserves the use of public IP addresses and allows multiple devices to share a single public IP address.

How does NAT facilitate communication between a computer on the Internet and a computer on a private network?

NAT translates the public IP address of an incoming connection to the corresponding private IP address of the device on the private network, enabling communication between the two.

What is the significance of IP version 6 (IPv6) in relation to NAT and IP address conservation?

IPv6 is a new generation of IP addresses that can produce over 340 undecillion addresses, eliminating the need for NAT and private IP addresses. With such a vast number of addresses, every device in the world can have its own public IP address.

Why will the adoption of IPv6 reduce the reliance on NAT?

The adoption of IPv6 will reduce the reliance on NAT because IPv6 provides an almost inexhaustible supply of unique public IP addresses, making IP address translation unnecessary.

What is the estimated number of IP addresses that IPv6 can produce, and how does this compare to IPv4?

IPv6 can produce over 340 undecillion IP addresses, which is a number with 36 digits after the 340. This is significantly larger than the 4 billion addresses available with IPv4, ensuring that there will never be a shortage of IP addresses.

Outlines

00:00

🌐 Network Address Translation (NAT) Overview

The script introduces Network Address Translation (NAT), a service used in routers to conserve the limited supply of IPv4 public IP addresses. It explains the historical context of IPv4's creation, where engineers initially believed 4 billion addresses would suffice, but later realized the need for a more scalable solution. NAT allows for the translation between private and public IP addresses, enabling multiple devices within a local network to share a single public IP address for internet access. This system is contrasted with the future potential of IPv6, which promises an almost inexhaustible number of unique public IP addresses for every device on the planet.

Keywords

💡Network Address Translation (NAT)

NAT is a method used in routers to translate a set of IP addresses into another set. It is crucial for conserving the limited number of IPv4 public IP addresses. In the video, NAT is highlighted as a solution to the problem of insufficient public IP addresses, allowing multiple devices to share a single public IP address.

💡IP Version 4 (IPv4)

IPv4 is the fourth version of the Internet Protocol, which provides over 4 billion IP addresses. The script mentions that engineers initially believed this number would be sufficient, but the rapid growth of the internet has made it necessary to find alternatives like NAT and private IP addresses.

💡Public IP Addresses

Public IP addresses are those that are registered on the internet and are necessary for devices to connect to the internet. The script explains that these addresses are limited, which is why NAT and private IP addresses are used to allow multiple devices to share a single public IP address.

💡Private IP Addresses

Private IP addresses are not registered on the internet and cannot be used to directly access the internet. They are used internally within a network, such as in a home or business. The script uses the example of a router assigning private IP addresses to internal devices, which are then translated by NAT to a public IP address for internet access.

💡Router

A router is a device that forwards data packets between computer networks. In the context of the video, routers are responsible for assigning private IP addresses to devices within a network and translating these addresses to a public IP address via NAT when internet access is needed.

💡Internet Service Provider (ISP)

ISPs are companies that provide internet access to customers. The script mentions that one could contact an ISP for additional public IP addresses for each device, but this would be expensive and inefficient, hence the use of NAT to conserve public IP addresses.

💡IP Address Shortage

The script discusses the potential shortage of public IPv4 addresses due to the limited number available (over 4 billion). This shortage is a driving factor behind the use of NAT and private IP addresses to allow multiple devices to share a single public IP address.

💡IP Version 6 (IPv6)

IPv6 is the latest version of the Internet Protocol, designed to replace IPv4. The script highlights that with IPv6, every device in the world could have its own public IP address, eliminating the need for NAT and private IP addresses. IPv6 can produce over 340 undecillion IP addresses, ensuring that there will never be a shortage.

💡IP Address Translation

IP address translation is the process of converting one set of IP addresses into another, as performed by NAT. The script explains that NAT not only translates private IP addresses to public ones for internet access but also translates public IP addresses to private ones for devices on a private network to receive communications from the internet.

💡Undecillion

An undecillion is a number with 36 zeros following the initial digit. The script uses this term to describe the vast number of IP addresses available with IPv6, emphasizing the impossibility of running out of addresses with such a large number.

💡Internet Growth

The rapid growth of the internet is a central theme in the script, as it led to the realization that the initial number of IPv4 addresses would not be sufficient. This growth necessitated the development of NAT and private IP addresses to manage the limited public IP addresses available.

Highlights

NAT stands for Network Address Translation, a service used in routers.

NAT's purpose is to translate a set of IP addresses to another set.

NAT helps preserve the limited amount of IP version 4 public IP addresses.

IP version 4 was created without anticipating the scale of the internet.

There were over 4 billion IP version 4 addresses available, initially thought to be sufficient.

Engineers developed private IP addresses and NAT to prevent a shortage of public IP addresses.

Public IP addresses are registered on the Internet and required for internet access.

Private IP addresses are not publicly registered and cannot directly access the internet.

Private IP addresses are used internally, such as in homes or businesses.

Routers assign internal devices private IP addresses.

Multiple devices in a home or business require access to the internet.

Acquiring additional public IP addresses for all devices is expensive and unnecessary.

NAT allows routers to assign private IP addresses and translate them to a single public IP address.

NAT translates both private to public and public to private IP addresses.

IP version 6 will eliminate the need for NAT and private IP addresses.

IP version 6 can produce over 340 undecillion IP addresses, ensuring no shortage.

Transcripts

NAT stands for network address translation and this is a service that is used in routers and

Its purpose is to translate a set of IP addresses to another set of IP

addresses and the reason for having the NAT service is to help preserve the

Limited amount of IP version 4 public IP addresses that we have available around the world

When the IP version 4 address was created engineers didn't realize how big the internet will become

Because even though there were over 4 billion IP version 4 addresses available

The engineers thought that that would be enough, but obviously they were wrong

so in order to prevent a shortage of public IP version 4 addresses

engineers developed private IP addresses and

network address translation

Now there are two different types of IP version 4 addresses there's public and there is private

Public IP addresses are publicly registered on the Internet

You have to have a public IP address if you want to go on the internet and there are

approximately 4 billion public IP addresses available

So they are limited

Now private IP addresses are different

Private IP addresses are not publicly registered. So you cannot directly access the internet with a private IP

Private IP addresses are only used internally such as inside a home or business

they are not used out on the public Internet and your router is what assigns your internal devices a

private IP

so for example

Most homes and businesses are not going to have just one device that needs internet access

Chances are that they are going to have multiple devices that need access to the Internet

So those devices need a public IP address if they want to access the Internet now

You could contact your internet service provider and ask them for these additional public IP addresses for all of your devices

But that's going to be more expensive

unnecessary and more importantly

It would also be a waste of public IP addresses and let's face it

if every device in the world had their own public IP address

We would have ran out of public IP addresses already

So instead we can have our router assigned the devices inside our home or business

Private IP addresses and when our devices need to access the Internet

Their private IP address will be translated by NAT in the router

To the one public IP address that we have been given. So again, this is what NAT does it

Translates a set of IP addresses to another set of IP addresses

So not only does it translate private to public but also translates public to private

Because if a computer out on the internet wants to communicate with a computer on this private network

Then the public IP address needs to be translated by NAT to the private IP address for that computer

now in the future

We won't need NAT or private IP addresses and this is because of the new generation of an IP address

Called IP version 6 with IP version 6 every single device in the world

Will have its own public IP address

So there is no need for IP address translation and this is because IP version 6 is able to produce over

340 undecillion

IP addresses, so that's the number

340 with 36 digits after it. So with a number that huge we will never run out of IP addresses