Hi Vince, when I joined the Org. they had external DNS entries in the DHCP Scope options for DNS Servers. When you did an ipconfig /all it would return the main DNS server's ip, the ip of the core switch, and the two external DNS server ip's. This is due to one area of the network not having internet access, which ended up being a switch config issue not being set up properly. I have fixed this switch issue so they are now all talking to each other...
I have also removed those external DNS entries in the DHCP Scope options and now only the internal DNS and core switch (also the gateway) display under DNS Servers results from ipconfig /all.
There seems to be something going on where not all clients can hit all internal devices (servers & printers) without a custom host file on the local machine. I am in the process of re-building the entire network and data center so I know with new network infrastructure this will get solved but I'm at the early stages of this and thought I could remedy this host file need prior to completing the network overhaul...
This is some advanced issue in relation to how the last guy set up the network, I'm just trying to peal the layers of this onion back to see if the need for the host files can be eliminated sooner than later...
Thanks,