Release 10.1A: OpenEdge Getting Started:
WebSpeed Essentials

Domain Name System

The Domain Name System (DNS) is one of the very useful, but often misconfigured, parts of any IP network. The job of the DNS is to resolve host names into IP addresses (and occasionally the reverse). If you misconfigure the DNS, then you will get some odd problems. The most common is that the client is taking a very long time to connect to the application server. This is probably due to a DNS issue where the DNS lookup is going outside your local LAN and onto your Internet Service Provider’s DNS servers.

If you are experiencing any problems at connect time, it is very important to check that your DNS is configured correctly. To do this, go to a prompt (either UNIX or a Windows Command prompt) and enter nslookup servername. The time it takes to respond is the DNS lookup time. It should be nearly instantaneous.

Note: If you are using a hosts file entry to “fix” this problem, then you really should fix the DNS problem and remove the entry in the hosts file.