Why can't I listen on 'localhost' but can I listen on '127.0.0.1'?

Question

I'm having difficulties understanding why the following line of code works in node.js:

server.listen(12345, "127.0.0.1"); // works

but this one does not:

server.listen(12345, "localhost"); // fails

Coding localhost literally results in the following error thrown:

events.js:45
        throw arguments[1]; // Unhandled 'error' event
                       ^
Error: ECONNREFUSED, Could not contact DNS servers
    at IOWatcher.callback (dns.js:74:15)

I do not understand why it should 'contact DNS servers' as it's localhost as defined in my HOSTS file (I'm using node.js under Windows).

Why doesn't hardcoding localhost work?

Answer 1

Are uou using cygwin build? Did you try 'Set up Domain Name Resolution (DNS)' :

Cygwin internally uses Windows for DNS queries. node.js uses the c-ares library that relies on /etc/resolv.conf. Cygwin ships with an empty /etc/resolv.conf. In order to enabled networking from your scripts, add these IPs to the file (Google Public DNS):

$ vim /etc/resolv.conf

nameserver 8.8.8.8
nameserver 8.8.4.4