[plt-scheme] Re: Newbie question about PLT web application

From: John Clements (clements at brinckerhoff.org)
Date: Tue Apr 21 00:02:18 EDT 2009

On Apr 18, 2009, at 10:20 PM, gadva wrote:

> Thanks for the quick reply,
>
> Sorry If I was unclear with the question, I just haven't had that much
> experience with setting up a web server before, and with networking in
> general so I'm not sure about the right terminology yet.
>
> I guess my question was how to setup the application to serve requests
> to users connecting to my server by typing http://serverIP:8000/myapplication.ss 
> .
>
> Because right now when I test it on a browser from within the server
> it runs ok, but when I attempt to connect from a different computer it
> does not work. So by using the code described above (and in the PLT
> Blog Application example from the website) (basically using web-sever/
> insta, serve/servlet) I am running the application on a selected port,
> so when a user connects to my IP adress with the correct port etc
> shouldn't the web server accept a request and respond with the HTML
> page that I define?

Speaking very generally, yes.

My guess is that the external requests are not reaching your web  
server, either because of a software firewall or because of an  
external network firewall.

One easy test is to try to contact the your PLT web server on the  
given port using a simple telnet client from another machine, e.g.:

my-other-machine% telnet serverIP 8000

If it goes through... well, I'd be surprised.  My guess is that it  
will fail, but it can fail in two very different ways: most firewalls  
refuse to answer entirely, in order to increase the cost of port  
scanning.  So if you get an immediate "server is not answering"  
message, then there's probably no firewall in place.  If you just get  
a stalled telnet, then there's probably a firewall in place.

FWIW, there are about 150 things that could be going wrong here; my  
confidence that I'm steering you in the right direction is only  
slightly higher than 50%.

All the best,

John Clements


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