Re: HTTPAPI example1 & example2

[Scott Klement <sk@xxxxxxxxxxxxxxxx>]

Hi Mike,

> Definitely a firewall problem. That last address is probably your internet
> address? Some kind of firewall?

If it's a firewall problem, why is he getting back a response asking him 
to specify a userid/password?  Surely, if a firewall is blocking port 
80, there'd be no way to send the 'You must log in message'.

I certainly agree that your tests with PING and TRACEROUTE have proven 
that there's a firewall in play -- but all you've proven is that the 
firewall is blocking PING and TRACEROUTE :)   TCP Port 80 may very well 
be wide open.

That's the problem with using PING/TRACEROUTE as a means of diagnosing 
an HTTP error.  Firewalls can block PING indepdendently of HTTP.  And 
can block TRACEROUTE independently of HTTP.  (and PING and TRACEROUTE 
independent of each other).  So you really can't determine anything with 
these tools.   These tools are really designed for someone who 
understands the network at hand, and is setting the network up and 
testing it, or is troubleshooting a bad component.   They're not useful 
when you don't know how the network supposed to work, or what is/isn't 
blocked.

I'd guess (and this is PURELY a guess) that Glenn's network has a 
reverse NAT device that looks for port 80 (specifically) and directs 
it's packets to a proxy or similar device with the intention of 
controlling who in the company is allowed to go to which sites, etc.

This probably has absolutely no impact on PING or TRACEROUTE.  But, for 
a totally different reason (and very possibly by a totally different 
device) ICMP is also blocked to prevent potential denial-of-service attacks.

Much more helpful than a ping or traceroute would be the data in the 
debug file generated by HTTPAPI.
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