[Samba] Mounting samba share from linux fails

[Mark Nienberg]

I have an old CentOS 6 machine that needs to mount a share from a samba
active directory. It was working when the AD DC was running samba 4.4.5,
but it stopped working when the AD DC was updated to 4.5.6. In both cases
the samba member server that hosts the share is running 4.5.6.

The version of cifs-utils on the CentOS 6 machine is 4.8.1.

The same samba share can be mounted successfully from a CentOS 7 machine,
which has cifs-utils version 6.2-9.

The verbose mount command looks like this:

[root at ftpServer ~]# mount.cifs --verbose //192.168.254.35/projects /mnt/smb
-o username=enginuser,domain=example.lan

Password:

mount.cifs kernel mount options:
ip=192.168.254.35,unc=\\192.168.254.35\projects,,ver=1,user=enginuser,domain=example.lan,pass=******

mount error(13): Permission denied
Any suggestions appreciated.

Mark