Cannot connect to Localhost:3000 for Rails but 127.0.0.1:3000 works

Question

I am learning Ruby on Rails with railstutorial.org and met this strange problem.

I ran "rails server" and the following information showed:

=> Booting WEBrick
=> Rails 4.0.4 application starting in development on http://0.0.0.0:3000
=> Run `rails server -h` for more startup options
=> Ctrl-C to shutdown server
[2014-04-02 01:28:18] INFO  WEBrick 1.3.1
[2014-04-02 01:28:18] INFO  ruby 2.0.0 (2014-02-24) [x86_64-darwin12.5.0]
[2014-04-02 01:28:18] INFO  WEBrick::HTTPServer#start: pid=13004 port=3000

I try connecting to localhost:3000 on various browsers and they all cannot establish a connection to the server.

I also tried rails server -p 3001 and connect to localhost:3001, which failed as well.

However, I tried 0.0.0.0:3000 , 127.0.0.1:3000, both of them worked and rendered the default welcome for rails.

Then I tried localhost:80, which successfully told me "It Works" and I can actually connect to my another local project using PHP+Apache.

So I really wonder why this happens and could anyone possibly give me any hint on it.

Thank you in advance:)

Are you able to telnet to the port, try this command telnet localhost 3000 — Rajdeep Singh
if you are on linux check hosts(cat /etc/hosts) file, it should contains this line 127.0.0.1 localhost — Kalpesh Fulpagare
Something you'll love is http://lvh.me:3000 -> it's a domain which points to your localhost, so you can test subdomains — Richard Peck

Sabyasachi Ghosh Sabyasachi Ghosh · Accepted Answer · 2014-04-02T06:05:46

Please check your host file. I assume you are using ubuntu then just type

sudo nano /etc/hosts

If the below line exists then ok else just insert the line.

127.0.0.1       localhost

And use localhost:3000 not Localhost:3000

Cannot connect to Localhost:3000 for Rails but 127.0.0.1:3000 works

2 Answers