host discovery in YaST2?

My YaST2 is not detecting one of my hosts. I went through my DNS setup and fixed a few things that were clearly wrong. This solved a few problems, but not the invisible host. The one that YaST2 isn't finding is the DNS Server itself. Is there some way to determine where this is breaking down? My DNS doubles as a firewall. That may well be misconfigured as was my DNS. TIA, Steve