Jtdylktuy

I think we need a little more information based on your question.

I'm going to guess you have a web server running to accept requests? I currently don't, and Safari won't connect to 127.0.0.1, because it "Couldn't find 127.0.0.1" - even though I can ping it just fine.

So first, you need to have something running. Secondly, have you tried connecting to testing.localhost with Safari, just incase the two entries are confusing Safari (this is entirely possible).

When you say "applications can connect as normal" with Chrome and Firefox, what are you seeing? The web page you're expecting to see? A different error?

Edit

I downloaded and installed MAMP, and I could not reproduce this error.

Some forum threads suggest IPv6 resolution is causing this issue. I would be inclined to turn off IPv6 and remove the entry from the hosts file (temporarily just for testing)

1. Apple Menu > System Preferences


2. Network


3. Select your Network Connection > Advanced


4. Configure IPv6 > Off

Apply, restart, and see how it goes.

I've had this happen before -- using http://computername.local/ worked for me, but I'm unsure why it would be different than just using a name in a host file.

Comment out the line:

::1         localhost 

from your /etc/hosts file. Apparently this would be caused by IPv6 support in Safari.

Some applications decide to bind to only a single interface - 192.168.13.37, for example, if that is the address assigned to eth0 or such - instead of using 0.0.0.0 for all interfaces.

Others might be using only IPv6 addresses ::1 (localhost) or :: (all interfaces). Try http://[::1]:8080/ in this case.

i'm not going to answer your question directly, but offer an alternative solution: use virtualhostx to manage the local DNS. See also if MAMP is not a good solution for your local development needs (if that's what you're after).

To ensure it's not an issue with your web server (like @nagul asked: what server are you using?), on my 10.6 Snow Leopard with IPv6 left at automatic, and even with 127.0.0.1 testing.localhost added to my /etc/hosts, the following works fine:

• Change the Listen port of the built-in Apache from 80 to 8080:
  sudo vi /etc/apache2/httpd.conf
  


• Run the built-in Apache by enabling System Preferences, Sharing, Web Sharing. Or restart using: sudo apachectl restart
  

Likewise, for me no problems using:

• python -m SimpleHTTPServer 8080

I know you stated you're not using any proxy. Just in case there's any doubt: recent versions of Firefox allow you to choose between Firefox-specific network settings (which was the only option in older versions), and the system settings. Safari always uses the system settings. Of course, good proxy settings would ignore local addresses (defaults on my Mac for Bypass proxy settings for these Hosts & Domains: *.local, *.lan, 169.254/16). Still, one could check if Firefox still works when making it use the system settings just like Safari. (Firefox Preferences, Advanced, tab Network, button Settings.)

(Anything in the server logs or Console logs? Which version of Mac OS?)