Internet Community Why is it important to have a public IP address?

The biggest ISP on the island made big announcements on its Internet offers recently. However, among those big announcements also came some subtle changes which many, including myself, did not notice.

Ish Sookun

2 min read min read
Photo by Muhammad Zaqy Al Fattah / Unsplash

This blog post is about the struggle of an Internet user in Mauritius to explain his Internet Service Provider about the importance of not breaking his Internet settings.

I am not going to elaborate on technical items and I might update this blog post in the coming days as and when I learn more about the complaint ticket provided by the subscriber.

Even if we do not have deep knowledge in computer networking, the very basic that most Internet users must have grasped by now is that an IP address is a numerical identity that keeps their device known on the global network called the Internet. When I am connecting to Twitter, the latter identifies my device with the IP address and upon successful login it can relate that I connected from that IP address.

Recently, Mauritius Telecom made changes to its FTTH modems and subscribers can no longer log in the device and change settings. In some cases, very basic settings like allowing the user to have a second SSID without password for guests.

Among the changes, it also seems that now Mauritius Telecom is putting every subscriber modem behind a NAT. To keep this part simple, let's say that normally when your home modem receives a public IP address it is connected directly to the Internet and thus is directly reachable to. Being behind a NAT means that the IP address is on the ISP's end and your modem only has a private address on the ISP's network. Therefore, your home modem is not directly reachable. Should you wish to run a server which needs to be accessible from the Internet, you cannot.

S. Moonesamy had his home network configuration perfectly set on the Mauritius Telecom's FTTH modem. That configuration was changed by Mauritius Telecom and it left him with a non-desirable home network configuration. He needs the bridge mode for his home network to work. Therefore, he emailed Mauritius Telecom and even tried to explain them the situation by phone. From what I understand he was told that his request for changing the modem config cannot be granted due to a security policy.

Usually, I expect people to give a copy of the policy when they cite such things, but in this case nothing was given to S. Moonesamy.

Was the Internet designed to operate on NAT?

No. This more than a decade old article in the IETF Journal explains how the IP address is a fundamental building block in supporting the Internet’s end-to-end architecture and NAT breaks that.

I hope that the ISP considers S. Moonesamy's request and does not engage in practices that break the proper Internet architecture.