Allright well I issued the following command with nmap

nmap localhost
For some reason it doesn't want to work all I get is an error which states the following :

Starting nmap 3.48 (http://www.insecure.org/nmap) at 2003-12-01 03:22 Eastern Time
Unable to determine what interface to route packets through to 127.0.0.1 QUITTING!
What does "unable to determine what interface to route packets through to 127.0.0.1 mean" ? Any suggestions or insight would be appreciated.