DHCPv6 from the router.
How does it work in Japan?
You want to cry? Or laugh, depending? On my side, that was crying.
So I need an IPv6 connection to test some servers configuration, from the comfort of my home office.
First, I try the fixed fiber connection.
My OpenWrt is v6 configured but has never seen an IPv6 around.
So I call the ISP who says that I need to fill a form to get IPv6 ; that'll take a few days, the IPv6 allocation is case-by-case... and there is no guarantee I might get one, depending on my location in Japan.
I was a bit intrigued (and worried) about the "get one", but... so be it.
Then try IPv6 from the phone company
I was a bit in a hurry, so I try with my phone provider ; my iPhone v11 knows how to deal with v6.
I call the support, they have to call me back because it's a pretty tecky matter. Sure.
Finally, I get to talk to someone tech-savvy who says...
"Actually, we cannot provide IPv6 right now, because we tend to stop supporting it...".
...
Back to the fixed fiber ISP
The location is ok, the support calls me to setup IPv6...
I need to switch off the modem, and switch it back on... They say to my surprise "you get one IPv6"...
So I checked OpenWrt: I indeed got a /128.
- me: what do you want me to do with that? I don't work directly from the router...
- them: actually you have to disconnect the router and plug the PC directly to the modem...
After a good hour of discussion, citing Iljitsch van Beijnum in his excellent IPv6 book (p.20),
"everyone gets a /48 unless they are absolutely, positively, never going to need more than a single subnet, in which case they get a /64".
So they said they're going to change the infrastructure, and by next March (2022), it'll be better...
NB1: the ISP has been assigned a /32 by JPNIC/APNIC in 2004...
NB2: changing of phone provider tomorrow