Problems when we added a sub domain

[Guest]

hey guys, this is a two part question. We've just added a sub domain to our
site. My problems are:

1. Sub-domain hosts can resolve the parent domain hosts, but the parent
domain hosts are unable to resolve the sub domain hosts, even if we use the
FQDN of the host. However, if we use the IP of the sub domain host, we can
see it (ping test). I tried an nslookup query in the parent domain, but still
can't resolve it. Did we miss something in the configuration of the
subdomain?

2. Not sure if this is a DNS problem. we demoted a DC in the subdomain, this
DC's roles has been transferred a month before demoting it. However, and i'm
not sure if the demoted DC is the cause of the problem, when i try to connect
to the subdomain from the AD console, i'm getting an error, cannot validate
domain: either the domain does not exist or cannot be contacted. But if i do
the same from the subdomain DC's AD console and connect to the parent domain,
it works fine.

Hope to here your thoughts on the above problems.
THANKS!

 

[William Stacey [MVP]]

1. Sub-domain hosts can resolve the parent domain hosts, but the parent

domain hosts are unable to resolve the sub domain hosts, even if we use the
FQDN of the host. However, if we use the IP of the sub domain host, we can
see it (ping test). I tried an nslookup query in the parent domain, but still
can't resolve it. Did we miss something in the configuration of the
subdomain?

I assume you added the delegation to the parent domain. What does dig or
nslookup tell you? Query the parent dns for a subdomain A record. What
does it say?

 

[Guest]

nslookup query fails using IP, hostname, fqdn.

I assume you added the delegation to the parent domain. What does dig or
nslookup tell you? Query the parent dns for a subdomain A record. What
does it say?