[Samba] Public share ask for a password

[c.buhtz at posteo.jp]

Hi,

I am using a Samba-server (2:4.2.14+dfsg-0+deb8u2) on Debian stable.
The Samba-client (samba-common ist 2:4.5.6+dfsg-1) runs on a Debian
unstable.

When I try to mount a Public share I am ask for a password. I don't
know why. There should be no need for a password. And I can log in no
matter if or which password I enter.

I can I prevent the password questions?

The is the IMO relevant part of my /etc/samba/smb.conf

[global]
   map to guest = Bad User
   usershare allow guests = no

[Public]
path = /Daten/Public
browsable = yes
guest ok = yes
writeable = yes

This is the relevant line in the /etc/fstab

//SPARKY/Public    /mnt/Sparky/Public    cifs rw,noauto,user 0 0

I am not sure on which side I did something wrong.