[Samba] Change of behavior samba 3.6 and 4.5

[john doe]

Hi,

I'm in the process of replacing my samba server 3.6.x (Debian wheezy, 
stable) to samba 4.5.x (Debian stretch, stable).

I'm facing one mageor opstacle:

When I do "net view \\<SAMBA-3-SERVER>" a list of the available shares 
is displayed.
But if I do the same command "net view <\\SAMBA-4-SERVER>" I get the 
following error:

"System error 5 has occurred.

Access is denied."

If I enter the username/password when prompted everything is working as 
expected.

Obviously, there has been some mageor changes between samba 3.x and 
samba 4.x but I can't seam to find an explanation for this behavior.

Is there a way to get the samba 3.x behavior on samba 4.x?

In other words: why do I need to enter credentials prior  to be able to 
"net view" the available shares.

-- 
John Doe