I am in a corporate environment, and we had a server that wasn't in DNS. I proved this by doing an nslookup on the server name, including just using the hostname and the FQDN , both failed. But I could ping the host without any problems. My hosts file was empty, and did an "ipconfig /flushdns" to clear the cache. I also checked the arp cache and only my computer was in there. After all that, I could still ping the host. I could also do an nbstat -a and connect to it. What I am wondering is how my ( and actually other Windows XP desktops, but no Windows 2003 servers ) could ping it, even though it was missing from DNS? Is there something about Windows ping that looks up the IP address from another source than the DNS server or hosts file or the DNS cache? Btw, I got the DNS guy to fix it. but it really made troubleshooting the issue of inter-server connectivity because all the desktops could ping the system that wasn't registered in DNS.

You are confusing a icmp reply with name resolution. icmp is ping which only returns if a live ip address dns isn't used in ping unless you ping by name dns is used to translate ip to name and name to ip

netbios winns "Best Practices", Event viewer, host file, perfmon, antivirus, anti-spyware, Live CD's, backups, are in my top 10

ping doesn't use netbios or wins for name resolution. "Ping the host name of a remote host to verify that you can resolve a remote host name. To do this, type the following command: ping Host name of remote host Ping uses name resolution to resolve a computer name into an IP address. Therefore, if you successfully ping an IP address but you cannot ping a computer name, there is a problem with host name resolution, not with network connectivity. Verify that DNS server addresses are configured for the computer, either manually in the properties of TCP/IP, or by automatic assignment. If DNS server addresses are listed when you type the ipconfig /all command, try to ping the server addresses to make sure that they are accessible." From here: http://support.microsoft.com/kb/314067

I was both pinging by hostname and performing nslookup by hostname. Pings were successfull, nslookup on the hostname could not resolve the hostname. By some method, the desktop computer was translating the hostname into an IP address, but the host was not in DNS, it was not in a hosts file, and if it was in DNS cache, it should have been cleared by ipconfig /flushdns. It was not in arp cache, which was irrevelant info now that I think of it. So, how was my computer resolving the IP? It does does primary/secondary WINS servers configured. One thing I noticed is the Windows 2003 servers have a single WINS server that is the same as one of their DNS server IP's, while my desktop has 2. So perhaps the 1 WINS server the Servers used did not know the host's IP address, but 2nd one did. That would explain my desktop being about to resolve the hostname to an IP address, while the Windows 2003 servers could not. After the Server guy put the host's IP address into DNS, then both servers and desktops could ping it.

where are the xp workstations pointing to for dns? Are multiple dns servers listed in the workstations tcp/ip properties?

wanderer already answered your question. The host doesn't have to exist in DNS in order to answer ping. And, if the entry isn't in DNS, then, as you found out, nslookup returns the message unable to locate. EEOC