Make a backup copy of your host file and then edit the original host file to look like this (it's the default OSX host file).

Code:
    
##
# Host Database
#
# localhost is used to configure the loopback interface
# when the system is booting.  Do not change this entry.
##

127.0.0.1                localhost
255.255.255.255    broadcasthost

::1                           localhost
fe80::1%lo0            localhost