this has to be a common question

[Eric]

I have 2 private ip subnets seperated by the internet.
A firewall at each location using NAT.

I have a server in the location B that I want to promote
to a DC for the location A, the server in location B in
not a member of any domain currently.

I have tried: pointing the dns of server location B to the
public ip that is mapped to the dc in location A.
Then on server A added a entry to the host file that has
the hostname of server B's public ip, and added an entry
to the host file of server B that has the hostname and
public ip for server A.

The server in location B can't communicate with server in
location A or even see the domain that server A is a dc
for.

 

[Peter Demeyer]

So I suppose the two servers can ping each other?
When you do a nslookup on server B, can the dns server resolve the DC in A's
name? And can it resolve SRV records? (set type=SRV etc.)?
Can you see DNS queries in the logs in location A's firewall?
Peter