Everytime I try to access the GPOs over the commandline for example with "samba-tool gpo listall" I get the following output:
root@samba4-1:~# samba-tool gpo listall
ERROR(runtime): uncaught exception - ('Could not find a DC for domain', RuntimeError('NT_STATUS_NETWORK_UNREACHABLE',))
  File "/usr/lib/python2.7/dist-packages/samba/netcmd/__init__.py", line 175, in _run
    return self.run(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/samba/netcmd/gpo.py", line 311, in run
    self.url = dc_url(self.lp, self.creds, H)
  File "/usr/lib/python2.7/dist-packages/samba/netcmd/gpo.py", line 117, in dc_url
    raise RuntimeError("Could not find a DC for domain", e)

All other samba-tool Commands ar working. I can create users and groups list fmos and so on.
Even with the option "-W EXAMPLE" as Workgroup and --ipaddress <ip-domain-controller> it's not working.
I user samba4 sernet-packages:
sernet-samba                       99:4.0.6-3  
on a debian weezy