Name vs. ip.addr. in the year 2008?

Here’s a problem I thought was history. In an environment with DHCP and DNS, I thought it was impossible to get things wrong. But obviously, I am the one who’s wrong.

I have been troubleshooting a Voicemail system with strange symptoms. Where among the strange log messages were: Could not locate %dbname% on server %hostname%. The database was running on the same server as the voicemail application, and name resolution was not an issue. Or so I thought. I tested name resolution through nslookup and tried to ping by using various names (hostname and fqdn). Everything seemed to be working. As a last desperate test, I changed the configuration in several places, to reflect the server’s ip-address instead of it’s hostname (inserted to the config by default during installation). Wonders of all wonders this solved my problems.