I have came across such a situation a million times where we move a machine from one IP to another (mostly when policy audits occur) and things stop working even though we modify DNS to reflect changes, just because some *beep* people still fiddle around with the old IP or some software were configured with IP instead of DNS (why? never got the answer, even though everyone knows DNS is here and hostnames are so much intuitive like a webserver having web.domain.com, an irc having irc.domain.com or in some cases chat.domain.com when we run multiple chat related tools like irc More >