[Samba] One of the DCs replication doesn't work

[Mitocariu Emilian]

Hi,

I have 2 DCs (dc1, dc2) on ubuntu 16.04 with samba 4.3.11 and another DC
(dc3) on ubuntu 17.04 with samba 4.5.8. The replication between dc1 and dc2
works, while dc3 is able to replicate data from the other DCs, but not the
other way around. If i try a manual replication this is what i get:

root at test-dc1:~# samba-tool drs replicate DC3 DC1 dc=domain,dc=com
Replicate from DC1 to DC3 was successful.
root at test-dc1:~# samba-tool drs replicate DC1 DC3 dc=domain,dc=com
ERROR(<class 'samba.drs_utils.drsException'>): DsReplicaSync failed -
drsException: DsReplicaSync failed (2, 'WERR_BADFILE')
  File "/usr/lib/python2.7/dist-packages/samba/netcmd/drs.py", line 348, in
run
    drs_utils.sendDsReplicaSync(self.drsuapi, self.drsuapi_handle,
source_dsa_guid, NC, req_options)
  File "/usr/lib/python2.7/dist-packages/samba/drs_utils.py", line 83, in
sendDsReplicaSync
    raise drsException("DsReplicaSync failed %s" % estr)

Both "host -t A" and "host -t CNAME" return correct information about DC3,
but "ping DCx.domain.com" works only for DC1 and DC2. I saw that other
people have this problem too but didn't find a fix for it. Could it be
because of different samba versions? Does anyone know how i could fix this?

Thanks