Thanks for the help 
It seems to only ever listen on 0.0.0.0. I made some screenshots from the command output and also my ip6table rules. I noticed, that i accepted tcp instead of tcp6 in the ip6table. Does that make a big difference?
uploading a file doesn’t work >.<
Ah and i managed to join with ipv6 on a server hosted on my own windows pc from another windows pc.
now i was able to read more info with netstat:
Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 493/sshd tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 1205/master tcp 0 0 0.0.0.0:8443 0.0.0.0:* LISTEN 1015/node tcp 0 0 0.0.0.0:25565 0.0.0.0:* LISTEN 1408/java tcp 0 0 127.0.0.1:12319 0.0.0.0:* LISTEN 605/shellinaboxd tcp 0 0 0.0.0.0:12320 0.0.0.0:* LISTEN 598/stunnel4 tcp 0 0 0.0.0.0:12321 0.0.0.0:* LISTEN 598/stunnel4 tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN 980/mysqld tcp6 0 0 :::22 :::* LISTEN 493/sshd