Long time ago I tried it out:

https://blog.acostasite.com/2013/02/publicar-prefijos-ipv4-sobre-una-sesion.html

https://blog.acostasite.com/2013/02/publicando-prefijos-ipv6-sobre-sesiones.html

I did not like, difficult troubleshooting in case something goes wrong (however I can understand it's a nice feature to have and in might be useful in some scenarios).

But you are right I do not know much about networks doing it, I also would like hear about it.

Alejandro,

Let's just jump all the arguing about lack of IPv4, the need of IPv6, and etc...

I must confess that I don't know all the RFCs.
I would like it, but I don't!

And today, I reached on https://tools.ietf.org/html/rfc5549

I knew that was possible to transfer v4 routes over v6 BGP sessions, or v6 routes over v4 BGP sessions.
But I got surprised when I saw this youtube vídeo of AMS-IX guys considering use a v6 only Lan, and doing v6 next-hops to v4 routes.

https://www.youtube.com/watch?v=uJOtfiHDCMw  

Well... I guess that idea didn't go to production.

But the questions are:
There is any network that really implements RFC5549?
Can anyone share some information about it?

--

Douglas Fernando Fischer
Engº de Controle e Automação