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Is there a dynamic DNS client for Linux which can update IPv6 at Cloudflare?

I have a router from my internet provider, which assigns both v4 and v6 addresses. And I'm using v6 to access my host from the outside because in this case, I don't need to monitor the router's IP changes. In theory, it shouldn't be complicated to implement on my own, but I wonder if there are some ready-to-use tools.

EDIT: I want to use dynamic DNS instead of manually assigned IP to make sure this host is always accessible from the outside, as my provider can change the IP range available for me.

German Lashevich
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I'm not that familiar with Cloudflare's services as I normally try to avoid public cloud services, but as they're a CDN, you most likely can add an origin server via a DynDNS name. And then you can use any DynDNS provider like https://dynv6.com/, Namecheap, ...

Usually, all you need to do to update your IP on your DynDNS provider is to call a web API (I.E., execute a single curl or Invoke-WebRequest call).

Dynv6.com has multiple APIs for this. The simplest one may be the DNS update via TSIG, followed by REST and SSH.

And from the Cloudflare documentation, it looks like they also support TSIG-based DNS updates. So you can probably take the example from the dynv6.com API documentation and use it with Cloudflare directly.

K. Frank
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Since I didn't find a suitable solution, I implemented a simple tool for that exact purpose. It is unsurprisingly named cloudflare-dynamic-dns.

It selects a first IPv6 address assigned to the specified interface, using Cloudflare API, checks if a configured DNS record should be created or updated and applies changes if needed.

German Lashevich
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Instead, get a static IPv6 allocation, so the AAAA records do not need to be frequently updated. This can be provider independent space, but does not have to be.

If your ISP does not provide this on their business class service, get a better ISP.

John Mahowald
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    "get a better ISP" - easy to say :-) Static IP was the first thing I checked out before digging into dynamic DNS, but it's not possible for me. – German Lashevich Jun 06 '19 at 20:53
  • Then complain to your existing ISP that they do not provide the services you require. Their IPv6 planning is inadequate if they cannot give you a static prefix out of their enormous allocation. – John Mahowald Jun 06 '19 at 23:29
  • @JohnMahowald, so you want to increase costs by 100x because you want to upgrade a "normal" home/business contract to an SD-WAN contract? So that you can get BGP and your own IPv6-PI space? Sounds like a joke. Advice like this is what gives a bad reputation to IPv6... You could have suggested a LISP or BGP-Tunnel provider, but you opted for this... – K. Frank Jan 23 '23 at 19:21
  • Getting a better ISP is trivial. Get a cheap VM at a hosting provide, use it to route traffic to your server. DONE. – TomTom Jan 23 '23 at 19:35
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    @TomTom only if you want to be treated with a lot of "Please turn off your VPN" messages from sites like Netflix and capture prompts because your traffic now originates from a datacenter instead of a residential IP space. But yea, you could delegate parts of a VMs IPv6 space towards your network through a VPN. But that was not the original suggestion either. – K. Frank Jan 23 '23 at 19:36
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    But it makes replacing your ISP trivial. – TomTom Jan 23 '23 at 19:48