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Thursday 28 Apr 2022 | 3 min read

What is CGNAT?

Carrier-grade NAT (CGNAT, also known as large-scale NAT), is a method of sharing a single unique public IP address with multiple services to allow providers to extend their pool of usable IPv4 addresses. This means your modem or router will be assigned a private IP address instead of a unique public IP address. Our network will then translate that into a shared public address allowing you to access the Internet.

Why is Aussie Broadband using CGNAT?

Our current pool of IPv4 addresses has been consumed and acquiring more gets exponentially more expensive each time, resulting in issues with scalability. Aussie Broadband has opted to use CGNAT as a method to share the current unique public IPv4 addresses that we own to multiple customers, helping extend the life of IPv4 within our network while IPv6 is still being deployed. IPv6 is still being adopted throughout Internet and is not a solution on its own at this time.

How does this affect me?

This will not affect the majority of Aussie Broadband customers and it should be business as usual, the only difference is that you will have a different IPv4 address assigned to your modem or router.

If you have purchased a static IP bolt-on or are a business customer there will be no change to your service and your IP address will not change, you will not be participating in CGNAT.

For residential customers, static IP addresses come at a cost added to your monthly bill. Visit the MyAussie® app or portal to purchase yours, or call our team on 1300 880 905.

What are some things that may not work with CGNAT?

There are some things that may depend on NAT and its features to work, this is services related to port forwarding and may include:

  • Servers: Web Servers, Email Servers, File servers and so on.

  • Home Utilities: Security Cameras and systems, home automation, Printers

  • Remote Access: Access to computers or devices remotely

If you have any concerns about these items please feel free to call our support team and have a chat.

How do I Opt-Out?

If you have a valid reason and need to opt-out of CGNAT you can call our technical support staff on 1300 880 905 and we can opt-out your service. Opting out of CGNAT will result in your unique public IP address changing unless you have a static IP applied to your service. If you have a static IP address you do not need to opt-out and will not be part of CGNAT.

What happens with my current static IP?

Nothing, if you have a static IP address on your service at the moment you will retain this address and not be part of CGNAT, your service should function unaffected by the roll-out of CGNAT.

What is an IP Address and NAT?

An IP Address is a unique address that is assigned to a device, this includes computers, phones, tablets and even network printers, every device connected to the network or the Internet needs its own address so it knows how to communicate. This is similar to how your house needs its own address so that it can receive mail.

IPv4 addresses come in 2 types, public and private.

Your public IP address is your address on the Internet and allows you to get online, every device that wants to communicate online needs to have a public address. The problem is we have run out of public addresses that are available and purchasing more is expensive. The current AussieBB model is to assign a single IP address per service.

A private IP address is what can be used internally but these do not allow connection to the internet as they are private or internal addresses but do allow your devices to communicate with each other. A technology called NAT is then used to translate the private address to public and allow all of your local devices to connect to the Internet.

NAT is a technology that has helped to extend the life of IPv4 by sharing one public address to multiple private addresses, this is what allows you to get online with all of your devices at home without having a unique and expensive address for each device.

What about IPv6?

Aussie Broadband is committed to delivering IPv6 as soon as possible, currently we are testing the deployment of IPv6 on selected connections and we look forward to sharing more news about this deployment when it is ready to be extended. Unfortunately we are not able to delay the roll-out of CGNAT until this is ready due to the limited addresses that are available.

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