To use my freenet6 account I made following changes:
root@pi:/etc/gogoc# diff gogoc.conf gogoc.conf.org
31,32c31,32
< userid=YOURACCOUNT_WITH_freenet6
< passwd=YOURACCOUNT_PASSWORD
---
> userid=
> passwd=
52,55c52
< #server=anonymous.freenet6.net
< server=amsterdam.freenet6.net
< # montreal has same account
< #server=montreal.freenet6.net
---
> server=anonymous.freenet6.net
74,75c71,72
< #auth_method=anonymous
< auth_method=any
---
> auth_method=anonymous
> #auth_method=any
88,89c85
< #host_type=host
< host_type=router
---
> host_type=host
108,109c104
< #if_prefix=
< if_prefix=eth0
---
> if_prefix=
293d287
< log_file=2
root@piIPv6:/etc/gogoc#
The line logfile=2 makes gogoc log verbously to /var/log/gogoc/gogoc.log