How do I check to see what domain I am joined to?

[AsherSevyn]

How do I check to see what domain I am joined to?

I am in a multi domain environment where I took one Samba file server from one domain to another and I need to make sure it is actually connected to the new server.
I have all the correct info in the smb.conf but I need some reassurance that I am actually connected.
This is a Microsoft environment. The Samba file server is the only Linux box on the network. What's the best command to view my domain membership?