I recently upgraded to Snow Leopard, and I want to start using the included Apache web server. I activated web sharing, and went to http:/127.0.0.1/ in my web browser. Safari couldn't connect to the server. Finally, using Network Utility, I found:
Port Scanning host: 127.0.0.1 Open TCP Port: 21 ftp Open TCP Port: 22 ssh Open TCP Port: 631 ipp Open TCP Port: 3306 mysql ...and so on...
I tried the same thing for 10.0.1.34, which is my LAN IP. Unless I'm very mistaken, this means that TCP Port 80 is not open on my computer. My 2wire router is forwarding port 80 to port 80 on 10.0.1.34, like it should be. My OS X Firewall is off, according to its Preferences pane.
How do I open up TCP Port 80?
EDIT: Well, it's semi fixed. I think it's a problem with the Apache server itself. I realized that I still had a copy of my old setup from OS X Tiger in /user/local/apache2. I ran the server in that location, changing the User and Group names in httpd.conf to "_www" as in the Snow Leopard default, and it worked great.
A weird hint that led me to that conclusion: the log files from the standard Snow Leopard setup of Apache hadn't been created. I assume that Apache ran into trouble before it could even start up (but for some reason didn't leave much evidence as to what went wrong).