Carrier Grade NAT

Carrier Grade NAT – What is it, what are CGNAT limitations

Published on Feb 11, 2023

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  2. Carrier Grade NAT - What is it, what are CGNAT limitations

Are you curious about the Carrier-Grade NAT (CGNAT) that’s revolutionizing internet connectivity?

As the number of devices connecting to the internet continues to grow, ISPs are facing a shortage of IPv4 addresses. CGNAT provides a solution to this problem by allowing ISPs to share a single public IPv4 address among multiple customers, conserving the limited pool of IPv4 addresses while still providing internet access to all.

Keep reading to learn more about a game-changing technology and take control of your online experience today!

Discover the benefits and limitations of CGNAT, and see how it can help you stay connected to the internet and how you can bypass some of the limitations.

Carrier-Grade NAT DEFINITION

CGNAT (Carrier Grade NAT) assigns a private IP address to each device on a customer’s network, then uses network address translation to map the private IP addresses to a single public IP address. This allows ISPs to efficiently manage their limited IPv4 addresses while still providing internet connectivity to their customers.

However, it’s important to note that CGNAT can have some drawbacks, such as making it difficult to host services on the internet and limiting the functionality of some internet-connected devices. Despite these drawbacks, CGNAT remains a widely used solution for addressing the IPv4 address shortage, and many ISPs continue to use it to provide internet connectivity to their customers.

Carrier-Grade NAT

I. What is NAT

NAT (Network Address Translation) is a technology that enables multiple devices on a local network to access the World Wide Web using a single public IP address. With the increasing demand for internet connectivity, ISPs are facing a shortage of available IPv4 addresses, which are the addresses used to identify devices on the internet. To address this problem, ISPs use Carrier Grade NAT (CGNAT) to share a single public IPv4 address among multiple customers.

II. What is Carrier Grade NAT (CGNAT)?

Carrier Grade NAT (CGNAT) is a type of NAT designed to meet service providers’ high-scale requirements. CGNAT assigns a private IP address to each device on a customer’s network and then uses network address translation to map the private IP addresses to a single public IP address. This allows ISPs to conserve their limited IPv4 address pool and still provide internet connectivity to all customers.

III. IPv4 Exhaustion – The History of IPv4

The history of IPv4 addresses can be traced back to the early days of the internet when the Internet Assigned Numbers Authority (IANA) was responsible for allocating IPv4 addresses to organizations worldwide. Over time, the number of devices connecting to the internet grew rapidly, resulting in a shortage of available IPv4 addresses. This shortage of IPv4 addresses led to the creation of Carrier Grade NAT as a solution to conserve the limited pool of IPv4 addresses.

IV. Is IPv4 Dead? How do I Migrate to IPv6?

IPv4 addresses are no longer being assigned by IANA, and IPv4 is not dead yet. However, with the increasing demand for internet connectivity, it’s becoming increasingly important to migrate to IPv6, the successor to IPv4. IPv6 provides a much larger address space, enabling internet connectivity to billions of devices without running out of addresses.

V. Standard NAT and IPv4 Addresses

Standard NAT is a basic form of NAT that is used to map a private IP address to a public IP address. This allows multiple devices from your local network to access the internet using a single public IP address. However, standard NAT does not provide the high-scale requirements needed for service providers.

VI. Ideally IPv6, NAT64 Not Withstanding

While IPv6 provides a much larger address space, many devices and services on the internet still use IPv4. To address this, NAT64 can be used to translate IPv6 packets into IPv4 packets, allowing devices and services that use IPv4 to communicate with devices and services that use IPv6.

VII. NAT64 Example

Consider a device on a local network that uses IPv6 to connect to a website that uses IPv4. To allow this connection to take place, NAT64 translates the IPv6 packets into IPv4 packets, allowing the device to communicate with the website.

VIII. Advantages of Carrier Grade NAT

CGNAT provides several advantages for ISPs and their customers. For ISPs, CGNAT allows them to conserve their limited IPv4 address pool and still provide internet connectivity to their customers. For customers, CGNAT provides a stable and uninterrupted internet connection.

IX. Proven Carrier Grade NAT Solutions

There are several proven CGNAT solutions available, including proprietary solutions from major technology companies and open-source solutions. ISPs can choose the solution that best meets their needs and the needs of their customers, but as always, there are also some limitations to this solution.

X. Carrier Grade NAT Alternatives

CGNAT is not the only solution to address the IPv4 address shortage. Other alternatives include IPv6 transition technologies, such as Dual-Stack Lite (DS-Lite) and Lightweight 4over6 (LW4o6), allowing ISPs to provide IPv4 and IPv6 connectivity to their customers. However, these alternatives may require significant infrastructure upgrades and may not be practical for all ISPs.

XI. Carrier Grade NAT Summary

Carrier Grade NAT (CGNAT) is a proven solution to address the IPv4 address shortage, providing ISPs with the ability to conserve their limited IPv4 address pool while still providing internet connectivity to their customers. While there are alternatives to CGNAT, such as IPv6 transition technologies, CGNAT remains a practical and efficient solution for many ISPs. It’s important for ISPs and their customers to understand the benefits and limitations of CGNAT and make informed decisions about their internet connectivity options.

Carrier Grade NAT Check

Carrier Grade NAT Limitations

While CGNAT can help ISPs to conserve IPv4 addresses, it also has several limitations that can affect the performance of some internet-based applications and services. These limitations include:

  • Limited connectivity: CGNAT can limit the number of simultaneous connections that a user can make to the internet. This can affect the performance of applications and services that require a high number of connections, such as online gaming and video conferencing.
  • Reduced security: CGNAT can make it difficult to identify the origin of a connection, making it harder to detect and block malicious traffic. Additionally, CGNAT can make it more difficult to establish secure connections, such as Virtual Private Networks (VPNs) and Secure Sockets Layer (SSL) connections.
  • Reduced reliability: CGNAT can introduce additional points of failure in the network, which can affect the reliability of internet-based applications and services.

As you can see, the use of CGNAT has some drawbacks, such as making it difficult for customers to host services on the internet and limiting the functionality of some internet-connected devices.

Fortunately, there is a way to bypass these limitations.
If you need full access to internet-based applications and services, such as online gaming, video conferencing, servers, or remote connection to a home surveillance system, then read our article on how to Bypass Carrier Grade NAT limitations using CGNAT VPN

Who uses Carrier Grade NAT

Carrier-Grade NAT (CGNAT) is commonly used by Internet Service Providers (ISPs) in countries where IPv4 address exhaustion is a concern. For example, ISPs in Europe and North America often use CGNAT to conserve their IPv4 addresses and manage the growing demand for internet connectivity. In some cases, even ISPs in developing countries may use CGNAT to conserve their IPv4 addresses and provide internet connectivity to their customers.

So, it remains a widely used solution to address the IPv4 address shortage, and many ISPs will implement CGNAT to provide internet connectivity to their customers.

Pros and Cons of CGNAT

Some CGNAT pros and cons:

Pros:

  • IPv4 address conservation: CGNAT allows ISPs to conserve IPv4 addresses by allowing multiple users to share a single public IP address.
  • Cost savings: CGNAT can help ISPs to reduce costs by allowing them to use a smaller pool of public IP addresses.
  • Increased network security: CGNAT can help to improve network security by making it more difficult for hackers to identify the origin of a connection.

Cons:

  • Limited connectivity: CGNAT can limit the number of simultaneous connections that a user can make to the internet, which can affect the performance of some internet-based applications and services.
  • Reduced security: CGNAT can make it difficult to identify the origin of a connection, making it harder to detect and block malicious traffic. Additionally, CGNAT can make it more difficult to establish secure connections, such as VPNs and SSL connections.
  • Reduced reliability: CGNAT can introduce additional points of failure in the network, which can affect the reliability of internet-based applications and services.
  • Complexity: CGNAT adds complexity to the network infrastructure and may require additional administration and maintenance
  • Lack of end-to-end visibility: CGNAT can make it difficult to troubleshoot network issues because it obscures the origin of the connection.

How can you check if you are using Carrier Grade NAT

If your ISP is using CGNAT, it means that your device is behind a shared public IP address, and you will have a private (internal) IP address assigned by the ISP.

Here are a few ways you can determine if your ISP is using CGNAT:

  • Check your public IP address: You can easily check your public IP address by visiting a website like whatismyip.com or ipchicken.com. If your public IP address is the same as someone else’s, it is likely that your ISP is using CGNAT.
  • Contact your ISP: Contacting your ISP and asking if they use CGNAT is the most straightforward way to find out. They should be able to tell you if your connection is behind a shared public IP address or not.
  • Check network information: You can also check the network information of your device to see if you have a private IP address assigned by your ISP. On Windows, you can do this by going to the Command Prompt and typing “ipconfig.” On Mac, you can do this by going to the Terminal and typing “ifconfig.” If you see an IP address in the range of 10.0.0.0/8, 172.16.0.0/12, or 192.168.0.0/16, it is likely that your ISP is using CGNAT.
  • Check router settings: If you have access to your router settings, you can check the IP address information to see if it is a public or private IP address. If it is a private IP address, then it is likely that your ISP is using CGNAT.
  • Traceroute: You can use the traceroute tool to see the path your network traffic takes from your device to a specific destination on the internet. If you see an IP address in the path that is not within your local network, it is likely that your ISP is using CGNAT. You can run a traceroute on Windows by going to the Command Prompt and typing “tracert <destination IP address>”. On Mac, you can run a traceroute by going to the Terminal and typing “traceroute <destination IP address>”.
  • Online CGNAT detection tools: Several online tools can help you detect if your ISP is using CGNAT. For example, you can use the “Test-NetConnection” tool in PowerShell on Windows, or the “nc” tool on Mac, to check if you are behind CGNAT.

While these methods can provide indications that your ISP is using CGNAT, the only reliable way to confirm is to contact your ISP and ask directly.

Check CGNAT using traceroute on Windows and Mac

To find out if you are behind the Carrier-Grade NAT (CGNAT) use traceroute on Windows and Mac.

On Windows:

  1. Open the Command Prompt: You can do this by pressing the Windows key + X, then selecting “Command Prompt” from the list.
  2. Type “tracert <destination IP address>” and press Enter: Replace “<destination IP address>” with the IP address of a website or server that you want to trace the route to. For example, you could use “tracert google.com”.
  3. Observe the output: The traceroute tool will display a list of the hops your network traffic takes to reach the destination IP address. Look for an IP address in the list that is not within your local network (i.e., not starting with “192.168.” or “10.”). If you see such an IP address, it is likely that your ISP is using CGNAT.

On Mac:

  1. Open the Terminal: You can do this by pressing the Command + Space bar keys, then typing “Terminal” and pressing Enter.
  2. Type “traceroute <destination IP address>” and press Enter: Replace “<destination IP address>” with the IP address of a website or server that you want to trace the route to. For example, you could use “traceroute google.com”.
  3. Observe the output: The traceroute tool will display a list of the hops your network traffic takes to reach the destination IP address. Look for an IP address in the list that is not within your local network (i.e., not starting with “192.168.” or “10.”). If you see such an IP address, it is likely that your ISP is using CGNAT.

It’s important to note that the output of the traceroute tool can be complex, and interpreting the results may require some technical knowledge. If you are unsure what the results mean, it may be best to contact your ISP directly for confirmation.

What are the private IP address ranges?

A private IP address is not intended to be reachable from the internet and is used for communication within a private network. The following IP addresses are reserved for use as private:

  • 10.0.0.0 – 10.255.255.255
  • 172.16.0.0 – 172.31.255.255
  • 192.168.0.0 – 192.168.255.255

These private IP address ranges are defined by the Internet Assigned Numbers Authority (IANA). They are commonly used for local area networks (LANs) in homes and businesses. Devices within a private network can communicate with each other using these private IP addresses, but they cannot communicate directly with devices on the internet that use public IP addresses.

When a device on a private network needs to communicate with the internet, it typically uses Network Address Translation (NAT) to translate its private IP address into a public IP address that can be used to reach the internet. This allows multiple devices on the same private network to share a single public IP address and access the internet.

How can I use the Test-NetConnection tool to check if I use CGNAT

The “Test-NetConnection” tool in PowerShell on Windows and the “nc” tool on Mac can be used to check if you are behind Carrier-Grade NAT (CGNAT). Here’s how:

On Windows:

  1. Open PowerShell: You can do this by pressing the Windows key + X, then selecting “Windows PowerShell” from the list.
  2. Type “Test-NetConnection <destination IP address> -InformationLevel Quiet” and press Enter: Replace “<destination IP address>” with the IP address of a website or server that you want to check the connection to. For example, you could use “Test-NetConnection google.com -InformationLevel Quiet”.
  3. Observe the output: The “Test-NetConnection” tool will display information about the connection to the destination IP address, including the local and remote IP addresses and the result of the connection. If the local IP address is a private IP address (i.e., it falls within the range of 10.0.0.0 to 10.255.255.255, 172.16.0.0 to 172.31.255.255, or 192.168.0.0 to 192.168.255.255), then it is likely that your ISP is using CGNAT.

On Mac:

  1. Open the Terminal: You can do this by pressing the Command + Space bar keys, then typing “Terminal” and pressing Enter.
  2. Type “nc -z <destination IP address> 80” and press Enter: Replace “<destination IP address>” with the IP address of a website or server that you want to check the connection to. This example uses port 80, which is the default HTTP port, but you can replace it with a different port if needed.
  3. Observe the output: The “nc” tool will display information about the connection to the destination IP address, including the result of the connection. If the connection is successful, then it is likely that your ISP is not using CGNAT. If the connection is unsuccessful, it may be due to various factors and not necessarily because your ISP is using CGNAT.

It’s important to note that while these tools can indicate whether your ISP is using CGNAT, the only reliable way to confirm is to contact your ISP directly and ask.

How to bypass cgn carrier grade nat to view IP camera?

If your ISP uses Carrier-Grade NAT (CGNAT), it may prevent you from accessing an IP camera directly from the internet. Therefore, you might need to use some techniques to bypass CGNAT and access your IP camera even if you are on a trip:

  • Use a VPN: A Virtual Private Network (VPN) can help you bypass CGNAT by encrypting your internet traffic and routing it through a server located in a different location. This will give you a public IP address that is different from the one assigned by your ISP and allow you to access your IP camera directly.
  • Configure Port Forwarding: If your router supports port forwarding, you can set up a rule to forward incoming traffic on a specific port to the internal IP address of your IP camera. This will allow you to access your IP camera from the internet by using the public IP address of your router and the port you specified in the port forwarding rule.
  • Use Dynamic DNS: If your IP camera has a dynamic IP address that changes frequently, you can use Dynamic DNS (DDNS) to map a hostname to your IP camera’s current IP address. This will allow you to access your IP camera using the hostname instead of the IP address, and the hostname will automatically update when the IP address changes.
  • Set up a reverse proxy: You can set up a reverse proxy on a server with a public IP address and route incoming traffic to the IP camera. This will allow you to access the IP camera from the internet using the public IP address of the server.

It’s important to note that some of these methods may require advanced networking skills and may also expose your IP camera to security risks. Before attempting to bypass CGNAT, it’s best to consult your ISP or a network professional to ensure that you do so safely and legally.

Carrier Grade NAT Pros and Cons

Pros and cons of solutions to bypass Carrier Grade NAT

Using a VPN

Pros:

    • Easy to set up and use
    • Encrypts internet traffic for privacy and security
    • Can provide a public IP address different from the one assigned by your ISP

Cons:

    • Can slow down internet speeds, especially if the VPN server is far away
    • May be blocked by your ISP or the IP camera
    • Can be expensive, depending on the VPN service you use

Port Forwarding

Pros:

    • Can allow direct access to your IP camera from the internet
    • No encryption of internet traffic, so speeds are not slowed down

Cons:

    • Requires advanced networking skills to set up and configure
    • Can expose your IP camera to security risks if not set up properly
    • May be blocked by your ISP or the IP camera

Using Dynamic DNS

Pros:

    • Easy to set up and use
    • Can allow direct access to your IP camera from the internet using a hostname

Cons:

    • Can expose your IP camera to security risks if not set up properly
    • May be blocked by your ISP or the IP camera

Setting up a reverse proxy

Pros:

    • Can allow direct access to your IP camera from the internet using a public IP address
    • Can provide encryption of internet traffic for privacy and security

Cons:

    • Requires advanced networking skills to set up and configure
    • Can be expensive, depending on the server you use
    • Can slow down internet speeds, especially if the server is far away

It’s important to note that the best solution to bypass CGNAT will depend on your specific situation and requirements, such as the location of the IP camera and your need for privacy and security. It’s best to consult with a network professional or your ISP to determine the best solution for your needs.

The easiest solution to bypass carrier grade NAT

Get VPN with a dedicated IP address and port forwarding to bypass Carrier-Grade NAT (CGNAT).

Pros:

    • A dedicated IP address ensures that you always have the same public IP address, even if the IP address assigned by your ISP changes.
    • Port forwarding allows you to forward incoming traffic on a specific port to the internal IP address of your IP camera.
    • Encrypting your internet traffic with a VPN provides privacy and security.

Cons:

    • Cost more, as dedicated IP addresses and port forwarding are not included in standard VPN packages.
    • It can slow down internet speeds, especially if the VPN server is far away. Therefore, choose servers close to your location.
    • If done by yourself, it requires advanced networking skills to set up and configure.

In general, using a VPN with a dedicated IP and port forwarding can provide a good balance between privacy, security, and accessibility, but it’s still important to consider your specific needs and requirements before deciding. For example, getting a VPN with dedicated IP and port forwarding from a service provider is a good solution if you don’t have a lot of technical expertise.

Read more: Bypass Carrier Grade NAT limitations using CGNAT VPN

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Magic

Hi! I’m Magic,

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During years of work on multiple projects, I noticed that most people struggle with technical questions, and sometimes finding correct answers is impossible on the congested internet.
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