I am looking into setting up a Samba domain controller using Ubuntu Server, for some Windows XP/7 clients, and I have one important question: Given the importance of DNS in a Microsoft Active Directory infrastructure, why do none of the setup guides mention configuring DNS to support a Samba domain?
I have installed an LDAP/Samba server in a test network that I will be attempting to join using an XP client very soon, but I'm just confused as to how the client will actually "discover" the domain - as I know this is how AD domains work.
I hope someone can shed some light on this!
Samba 3, the current version, does not use the active directory protocols. Instead it uses the older NT4 domain protocols. As Jasper mentioned, this uses NetBIOS for lookups which uses broadcasts. You might want to consider setting up Samba as a WINS server, if you have more than one subnet its a requirement.
If you are using a Samba4 alpha which does use the AD protocols then you will need a DNS server. There are some brave souls that are using Samba4 in production without major issue, it is actually quite stable.
NetBIOS uses its own lookup mechanism, that's what the nmbd daemon is busy with.
I don't know about AD domains, but samba domains only use DNS for dynamically mapping windows workstation hostnames from NetBIOS lookups to DNS, so non-windows workstations can reach them by name. This is by no means compulsory, though.
Netbios or WINS resolution is far more commonly used with Samba and DNS is optional resolution method depending on how you have configured your clients.
Netbios or WINS is not required to use Samba. If you disable netbios almost all SMB clients will attempt to use DNS resolution.
From the the howto
There are some ancient clients that don't support using DNS. But most SMB clients that do not support DNS also do not support TCP/IP.
This article includes ways you can configure your windows clients to use wins,
Have you checked out SAMBA AD Ubuntu
for CentOS
When setting up samba 3 as a domain controller a WINS server is required if you do not currently have one on the network. Otherwise your windows clients will have no way to locate the domain controller.
This is simple and can be enabled by setting wins support = yes in the smb.conf.
After enabling this option, restart samba and wait 10 minutes. Then on your linux box locate the wins.dat entry and you should see a list of your windows clients on the network.