UDP protocol failed, as well as IPv6. pkgsrc blocked because of ths(IMHO)

[spermwhale_warrior]

right into the installation I couldn't install pkgin because the UDP protocol wasn't working well : 'ping6: UDP connect: no route to host'
then after 'ftp: can't connect to '2001:470:1f05:3d::21:80'
At the first boot, I saw that my hostname wasn't set by default.
Can I set anything I want ? Because I am on a box with dhcp and (it says) support for ipv6.
Now, pkg_add echoes 'no packet found' for whatsoever I ask for,
ping google.fr works, but not ping6. It says too : UDP conect: No route to host.
I tried ping6 with linux mint on my laptop, it works well and the box says it provides support.
The result of rtsol re0 is : kernel is configured no to accept RAs.
I did not touch anything after the first boot.
I would like, in the end, use pkgin. In fact, I study computer science and I needed something that doesn't crash on my computer within thirty days after installation, something which I surprisingly didn't find for now.
My version is NBSD 6.1.4, for amd64
Thanks !