[Samba] Force logonserver in samba4

[Iñigo Martinez Lasala]

Hi everybody.

We have a samba4 domain deployed across serveral countries. Some of them 
(overseas) have a poor VPN connection with mainland.
Since Samba4 does not support (yet) subtrees, we have deployed a DC in 
each location for domain validation. However users in mainland logon 
randomly at overseas location and sometimes this is a problem due to low 
bandwidth available.
Is there any way to contraint logon servers? We have though about two 
options:

- Limit, via firewall rule, login at oversea locations from mainland, 
but we are not sure if this will a problem or delay in excess logon process.
- Limit DNS replication so at mainland office no oversea DCs entries are 
shown, but this would be quite complicated to implement.

Any hints?

Thanks in advance.