When you are using a Linux system and checking your public IPv6 address, you may notice that it is different from the one listed in Linux. This can be confusing, especially if you are new to networking and IP addresses. In this article, we will explain why this discrepancy occurs and what you can do about it.
First, let's understand what an IP address is. An IP address is a unique identifier assigned to each device connected to a network. It allows devices to communicate with each other over the internet. There are two types of IP addresses - IPv4 and IPv6. IPv4 addresses are the older version and use a 32-bit format, while IPv6 addresses are the newer version and use a 128-bit format.
Now, let's dive into why your public IPv6 address might be different from the one listed in Linux. The most common reason for this is that your internet service provider (ISP) is using a technique called Network Address Translation (NAT). NAT allows multiple devices in your home or office to share a single public IP address.
When your ISP assigns you an IPv6 address, it is typically a global unicast address. This address is unique and routable on the internet. However, when your traffic leaves your local network and reaches your ISP's network, it goes through a NAT process. This means that your global unicast address is translated into a different address before it reaches its destination.
Linux, on the other hand, shows you the local IPv6 address assigned to your device. This address is unique within your local network but not routable on the internet. It is used for communication within your network and is not visible to devices outside your network.
So, when you check your public IPv6 address using online tools or websites, you are seeing the translated address assigned by your ISP. This address is the one that other devices on the internet see when they communicate with your device.
Now that you understand why your public IPv6 address is different from the one listed in Linux, you might be wondering if there is anything you can do about it. Unfortunately, since NAT is controlled by your ISP, you have limited control over this process.
However, if you need to access your device from outside your network using its public IPv6 address, you can set up port forwarding. Port forwarding allows you to specify certain ports on your router that should be forwarded to your device's local IPv6 address. This way, when someone tries to access your device using the public IPv6 address, the traffic is correctly directed to your device.
In conclusion, the reason your public IPv6 address is different from the one listed in Linux is due to the NAT process performed by your ISP. This process translates your global unicast address into a different address before it reaches its destination. While you have limited control over this process, you can set up port forwarding on your router to access your device using its public IPv6 address.