@Box293:
What do you mean by activate? Perhaps I'm missing something.
By default, no IPv is assigned to the WAN (or comparable) interface.
I didn't find a dhcp client running that uses "scan" WAN style interfaces which checks if the upstream provides an IPv6.
Btw : setting up manually the config.xml is of course the way to go - and you can definitely consider yourself as a not-pfsense-dummy if you pulled that one off :)
@Box293:
with a WAN connection that provides IPv6 via DHCPv6+PD, pfSense 2.3+ will request a /64 prefix and assign it to the LAN
Which means, when booting, some DHCP-client look-alike is executing to obtain an IPv6/[whatever], putting an IPv6 on WAN and init LAN with an IPv6.
(are you sure ? - all this 'out of the box' without any user preparation ?)
Again : I'm not advertising that I know a lot of IPv6, I use the "tunnel" proposed by he.net. It work quiet well, but isn't really a native solution. I consider it as some sort of "plan B". My ISP is Orange, the biggest in France, 16 million 'victims', sorry => 'clients' - and they still don't know what "IPv6" is. During the last 6 years they are 'testing it' ….. (and right now, they are probably are in strike again ;)).