[Samba] Multihomed AC DC Server and subnets

[Federico Alberto Sayd]

Hello:

I am currently planning to divide our network in smaller subnets. Our 
central server is a Samba AD DC File Server also acting as DC.

My plan is subnet our current network, add a new interface for each 
subnet in the  Samba File Server and configure it to listen in all new 
interfaces.

Questions:

1 - Does this multihomed configuration have any drawback, specifically 
because AD relies so much on DNS to work, and hosts in each subnet need 
resolve to the right ip of the multihomed server?

2 - Do I need to configure new sites for each subnet from "Active 
Directory Sites and Services" and install a new DC in each subnet?

3 - Can you suggest a way to avoid that pcs placed in a different subnet 
other than the File Server can reach the File Server without routing 
(The File Server will have a interface in each subnet)?. I assume that 
pcs reach the File Server by name and a name only resolve to a unique ip.

Can you drive me in some direction or point me if this approach is the 
right choice?

Thanks

PD: Sorry for my poor English