ping: cannot resolve localhost: Unknown host OS X

Question

127.0.0.1 localhost
255.255.255.255 broadcasthost
::1 localhost 
fe80::1%lo0 localhost

This is my /etc/hosts file but it's really strange failure to ping and cannot resolve localhost.

It's work well like ping gonjay when I add

127.0.0.1 gonjay

to my hosts file.

Answer 1

I fixed it by making sure that hosts file used Unix line endings (I used Sublime Text for this)

Answer 2

I have solved the problem by restoring my Hosts file (it was empty):

But before, you have to check your hosts file.

cat /etc/hosts

If nothing is shown, that means your hosts file is empty.

Then just copy and paste this over the existing hosts file then save it as plain text to restore it.

##
# 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

If your hosts file is not empty, your can try to delete it and add it again with this lines.

Answer 3

Probably will help for those who don't know how make Unix line endings

brew install dos2unix
sudo dos2unix -c mac /private/etc/hosts

That will convert your perfectly fine hosts file to UNIX encoding.