[fChk]

PS: I think those boxes are LXD system containers (see the output of the `df -Th` command.)

Well, it turns out that they are indeed LXD/LXC system containers, which makes me wanting to explore/dig more into them. I've downloaded the adhoc snap packages and need more time to deploy a working testing space for them.. This will certainly be a topic of an upcoming thread when achieved.

The question that intrigued me the most: is there really a difference between an application container (like docker's) and a system container (like LXC/LXD's) ?... The answer is.... Not really, technically speaking!... just a marketing spin from Canonical (the horse-power behind LXD development) to cut a market share from the current dominance of Docker in the Container tech space.


UPDATE:
Just wanted to comment on this too:

Hey there!.. Thanks for your willingness to help; but you missed my point. Right before the part you're quoting, there is this:
The key word there being directly, so, if you know of any public NAT46 gateway or any IPv6-tunnel broker supporting AYIYA protocol then you'll be of a great help :-)

Right now, I'm using SSH tunneling via my NanoKVM box to get the job done; hence there is no need for the solutions you mentioned. Besides, NanoKVM explicitly forbids running VPNs.

I succeed in logging into those IPv6 boxes directly from home; thanks to the IPv6 Teredo Tunnelling; see RFC-4380: Tunneling IPv6 over UDP through Network Address Translations (NATs).

There is an implementation of it on Linux called `miredo`, but Fedora doesn't ship it any more. Thus had to compile it from source; the only dependency it needed was 'libcap-ng-devel'.

This whole IPv6 connectivity was really off my radar all this time. Thanks to these IPv6-only VPS's opportunity, I finally have the motivation to dig into it.

Resource:
Gihub repo of the miredo source: https://github.com/multiSnow/miredo