obtain data for ms-DS-ReplicatesNCReason

[tridge at samba.org]

Hi Cristian,

 > where, in Samba 4 code, can I find that information to put it on the
 > ms-DS-ReplicatesNCReason field during replication? I have no idea where I
 > can query topology-related data.

We don't currently have any functions for querying the topology of our
replication, because our replication doesn't currently have any
topology! We just always create connections to every other DC.

For the purposes of your question, you should probably just hard code
NTDSCONN_KCC_RING_TOPOLOGY. It isn't correct, but it will do until we
start to properly support the ring+shortcuts topology used by AD.

Alternatively, you could start working on adding support for real
toplology logic in dsdb/kcc/, perhaps creating a new module
kcc_topology.c. To do that you'll need to read through the MS-ADTS
documentation on how to work out the correct links for the
topology. To start with, you could look at MS-ADTS section 3.1.1.1.13,
but I think you'll need to read quite a few other sections as well.

Cheers, Tridge