This Debian Squeeze server is located inside a Windows network, and it's DNS servers in resolv.conf are set to Domain Controllers which are also DNS servers.

In this setup, a DNS lookup for gc._msdcs.<domain> correctly returns the IP addresses of the Global Catalog servers on the network.

When trying to communicate via these special DNS names however, things do not work.

For example:

ping gc._msdcs.<domain>

returns unknown host.

Also, trying to communicate using the ldap protocol using the same DNS name does not work.

As soon as I use just ping <domain> or ldap to just <domain> (which returns all DNS servers in the domain), it works fine. This works for us, but only because all our DCs are also GCs adn DNS servers.

I checked and re-checked, and nslookup gc._msdcs.<domain> always returns the correct results.

I've also checked using both ping and ldap on a windows machine and that works perfectly using gc._msdcs.<domain>.

Lastly, I've tried the same tests on another Debain Squeeze server and the results fail in exacatly the same manner as this one.

I wonder if it's something to do with the underscore?

Thanks - Lawrence