Forum OpenACS Q&A: Response to why cannot see the pages outside of my machine?
The default behavior for nssock (e.g., ns_param address) is not a secret; it is clearly documented in the AOLserver Administration Guide: http://www.aolserver.com/docs/admin/con-ch3.htm. As I mentioned before, this is typical UNIX web server behavior (Apache, Netscape, NCSA httpd), and this has certainly been the case with AOLserver since version 2.3.
A typical UNIX newbie error is to alias a hostname to the loopback address (127.0.0.1 localhost); I really discourage people from messing with the loopback address. If you need to set up a bogus hostname/IP address, use a dummy network interface: that's what it's there for.
Because of its very nature, the essentials of TCP/IP networking are best learned in a workshop/classroom environment, i.e., several people working together. I'm generally a do-it-yourself type, but networking is one topic that do-it-yourselfers really lose most of the intrinsic value of working together with other people. You and others will likely make different mistakes. Learning to solve network problems together will help your networking knowledge enormously. If you've ever tried to debug a networking problem with someone else (e.g., ISP help desk), well, you probably know what it's like.
Some Linux User Groups (LUGs) apparently have install fests; these would be pretty good places to have TCP/IP network administration workshops; I don't know if groups generally do this though.
One of the biggest errors ACS/OpenACS newcomers make is not taking a methodical approach and just plowing through the ACS/OpenACS installation willy-nilly without verifying if the individual steps were correctly done (the number one and two problems were messing up the nsd.tcl and ad.ini configuration files).
As the author of the very first "ACS on Linux" tutorial, I admit that my articles certainly did not offer a great variety of tests, but I did mention some things that could be tested (e.g., serve up static HTML pages on AOLserver before compiling the ArsDigita Oracle8 database driver). If I remember correctly, there used to be a Pset 0 that required a certain amount of knowledge in a *nix environment (sort of like remedial English Composition for crappy writers like me); there was probably a section on learning Emacs.
I never thought that I had the ability to teach *nix system administration in 30 minutes (or even in a couple of hours) and I clearly pointed out my shortcoming in my articles (now mercifully a part of the Great Internet Null Device in the Sky). If you don't know *nix, get a basic sysadmin book and read it.
As to why the OpenACS 3.x config files are the way that they are: it's just legacy crap. OpenACS 3.x derives from ACS Classic Tcl 3.x. Originally ACS Classic was built on http://photo.net, a "Big Iron" HP-UX server at mit.edu that had over 11 network interfaces (I remember, because the original Oracle 8.0.x to Oracle 8.1.5 upgrade failed due to a certain Oracle bug). Thus, the ACS sample nsd.ini file was built on a machine that needed to define an individual IP address and hostname, because there were other web servers running on the same machine (e.g., homepage.lcs.mit.edu - or something to that nature). A little piece of worthless ACS trivia; I can't believe I reserved some neurons to remember that...