title: Only IPv6 Only. --- pub_date: 2020-03-04 --- author: ungleich --- twitter_handle: ungleich --- _hidden: no --- _discoverable: no --- abstract: In this article you will learn why it is beneficial for you to go IPv6 only instead of dual stack. --- body: ## TL;DR IPv6 is a solution to the address sparsity in legacy IP (IPv4). Only if you stop using legacy IP, you really profit from IPv6. The good news is, this has become rather easy nowadays. ## Current situation As of 2020-03-04, legacy addresses are hard to get and are becoming increasingly more expensive. In fact, almost [all 5 global IP address registries are out of legacy addresses](https://ipv4.potaroo.net/). What does that mean in layman's terms? If you are having one or more dedicated legacy IP addresses, your bills will go up in the near future. In fact, [google started increasing prices last year already](https://www.techrepublic.com/article/google-cloud-charging-for-ipv4-but-proper-ipv6-support-is-still-missing-in-action/). It is just a matter of time, until others have to follow. ## Legacy IP world reachability One clarification: even if you go IPv6 only, **you can, will and want still legacy IP world reachability**. When you surf with your mobile phone, when your home or company accesses the Internet, you still need access to websites that are running on legacy IP. Also, if you are running a server, a virtual server, a website or any other service, you probably want to be reachable from legacy IP clients. Good news is: **you don't need a dedicated legacy IP address** for any of this. Neither to reach the legacy Internet, nor to be reachable. ## History repeats You might remember that in the nineties, https webservers required a dedicated **IP address per domain**. That's true. If **example.com** and **example.org** were both using SSL certificates, the webserver required at least 2 IP addresses. Later the SSL protocol was improved to allow domain names to share one IP address. Today one IP address can host hundreds or thousands of domains on a single IP address. With the shift from legacy IP to IPv6, we can use the same principle again. Instead of having a dedicated legacy IP address per service, **we can share legacy IP addresses**. ## Dual Stack is not a solution Operating dual stack networks or services does not solve the problem, because it still uses legacy IP. In fact, the [US government mandates 80% IPv6 only networks by 2025](https://www.theregister.co.uk/2020/03/03/us_government_ipv6/) ([original website](https://www.cio.gov/assets/resources/internet-protocol-version6-draft.pdf)). For a good reason, because they want to reduce complexity. And costs, obviously. While there might be situations in which dual stack is required, in general * dual stack is more complex * dual stack does not remove the costs * dual stack almost always can be replaced by IPv6 only plus a gateway translator Even if you are not using public IPv4 space, you can still save costs with going IPv6 only: whenever you connect to a VPN, whenever companies merge networks, even [when you only run docker](../how-ipv4-stops-me-from-working-in-the-train/): with [private ip addresses](https://en.wikipedia.org/wiki/Private_network) you can easily run into overlapping addresses. This costs time and in the end resources. ## Going IPv6 only This brings us to the main topic of this article: going IPv6 only. It is possible to IPv6 only, but still connect to the legacy Internet. But how does this work in practice? ## Going IPv6 only with your static website It is very easy to create a static website on an IPv6 only webserver and have it reachable from IPv6 and the legacy Internet: you can either [create an IPv6 only virtual machine](../ipv6-only-hosting/), setup a webserver on it and use the [IPv4 to IPv6 proyx](../ipv4-to-ipv6-proxy/). Or, if you want to have it much easier, you could go with [IPv6 enabled webhosting](../zerocarbon-webhosting-with-ipv6/) directly. ## Going IPv6 only network ## Going IPv6 only ## Going IPv6 only bittorrent If you want to publish your open source software or publicly available data via bittorrent, you need can seed it from any IPv6 reachable computer. We provide an [IPv6 torrent tracker](../projects/ipv6-torrent-tracker/) ## Who is profiting from IPv6 only vs. dual stack? ## How does this affect me? ## Short review Long story short, IPv6 was mainly introduced to fix the address sparsity issue in IPv ## Dual stack setups introduced as ## ## The changes of IPv6 to the world In the next articles we will describe some real, practical changes of what we use and how we can work differently with IPv6. If you already have suggestions, we are happy to read them on **ipv6 at ungleich.ch** or on the [IPv6 Chat](https://IPv6.chat). Meanwhile, if you are interested in giving IPv6 only VPS a try, there is a 50% discount only until [Black IPv6 Friday](https://swiss-crowdfunder.com/campaigns/black-ipv6-friday?locale=en).