5
The host is behind NAT and uses Teredo to get globally routable.
How to make it easily-reachable? For IPv4 case we just use no-ip or dyndns, however for ipv6 I don't see AAAA replies from dyndns's nameserver even though I specified "IPv6 Address (optional)":
$ dig vi.dyndns.org @ns1.dyndns.org | grep -v '^;'
vi.dyndns.org. 60 IN A 1.2.3.4
...
ns1.dyndns.org. 60 IN A 204.13.248.75
ns1.dyndns.org. 60 IN AAAA 2600:2001::75
...
(I was expecting to get):
vi.dyndns.org. 60 IN A 1.2.3.4
vi.dyndns.org. 60 IN AAAA 2001:0:53aa:64c:c5b:4f1e:a9c6:61b1
...
How to make my host known in IPv6 world? Are there services like dyndns or no-ip, but for ipv6?
You shouldn't use Teredo for services. You really should use that as last resort, for clients.
But yes, if the service supports IPv6, it usually have a parameter for setting IPv4 or IPv6 address. And if you want to have different auto-selected, they usually uses two different URL:s.
And yes, there are other tunneling services. I uses HE services in https://tunnelbroker.net/, there are others. :-)