[Samba] Samba 4 AD trust an old samba 3 NT4 domain

[Giuseppe Ravasio]

Hi,
I would like to create an external outgoing trust from a Samba4 AD
domain to an old Samba3 NT4 domain.

I'm getting this error:

root@:~# samba-tool domain trust create OLDDOMAIN --type=external
--direction=outgoing -Ugravasio

LocalDomain Netbios[NEWAD] DNS[newad.modiano.com]
SID[S-1-5-21-123456789-1234567556-3271483883]
ERROR: Failed to find a writeable DC for domain 'OLDDOMAIN'

Running the command with -d10 says at the end:
finddcs: NBT <1c> response 0 at '172.16.xx.xx'
finddcs: performing CLDAP query on 172.16.xx.xx
finddcs: No matching CLDAP server found

I wonder if this type of trust is supported at all by Samba?

Thanks
Giuseppe