Hello I actually have two Samba4 DCs on a main production site. We have several remote sites where users authenticate on our main DCs through VPNs. We would like to add an additional DC per site. Do we have to set something particular or do we have to simply add an additional samba4 server per site with samba-tool domain join mondomaine.lan DC -U administrator --realm=MYDOMAIN.LAN -W MYDOMAIN For information we have almost 100 sites, that means potentially 100 secondary DCs. Is it possible or is there a limit that samba4 can support in terms of number of replicated DC's ? I guess the best way is to use Active Directory sites feature. https://wiki.samba.org/index.php/Active_Directory_Sites One last question about provisionning secondary DC (with or whitout site options), is it mandatory to specify the dns-backend option ? For example if the master has been provisionned with BIND9_DLZ backend, do I have to specify it during the join of a remote DC ? Regards, Julien