Antivirus / Internet security blocking communication with web service

[Jared]

I've got an app that requires communication with a remote web service.
I've had customer reports of the "underlying connection was closed"
error, and I assume this to indicate they've got Internet security
software running that's blocking the connection.

However, I don't have the luxury of doing Remote Desktop with them, and
they often have no idea if they're running any Internet security
software.

Is there a way to programmatically figure out what could be blocking
outbound traffic on ports 80 and 443? I've considered getting a list
of running processes and checking it for known offenders (e.g. Norton,
McAfee, etc), but I'm hoping there's a more explicit way to determine
what's blocking my app.

TIA

Jared

[Vadym Stetsyak]

> Is there a way to programmatically figure out what could be blocking

outbound traffic on ports 80 and 443?

Actually you can't. While doing their job firewalls block connection
silently,
they do not send response about the resons of blocking packets.

IMO what you can do, is to perform research and find out if there are any
firewalls installed on the system. ( You can do that programmatically, but
there is no
unified approach to this - every firewall can be detected only by some
special signs e.g. registry keys ).
And after detecting firewall you can their rules in order to determine if
they block 80, 443

--
Regards, Vadym Stetsyak
www: http://vadmyst.blogspot.com

[Jared]

Bummer, but I figured that was the case.

If anyone can point me to a list of registry keys or executable names
for known firewalls, I'd appreciate the time-saver. I'm not about to
purchase and/or install "internet security" software on my machine! :)

[C-Services Holland b.v.]

Jared wrote:

Bummer, but I figured that was the case.

If anyone can point me to a list of registry keys or executable names
for known firewalls, I'd appreciate the time-saver. I'm not about to
purchase and/or install "internet security" software on my machine! :)

How about an external hardware firewall blocking those ports. No
executable name for that.
--
Rinze van Huizen
C-Services Holland b.v

[Jared]

These customers are not likely to be that sophisticated. Besides, it's
pretty unusual to have a hardware firewall blocking outbound traffic on
80/443. No consumer-grade firewalls that I'm aware of are factory set
to block outbound traffic, anyhow.

I've revised the app to provide the standard warnings about
computer/network configuration supporting Internet access.

Thanks for the suggestions.