Solved

determine if firewall is blocking my app thru vb6 code

Posted on 2010-08-13
4
342 Views
Last Modified: 2012-05-10
I have had an ongoing problem with my app that sends info to me using my online jmail component.
In about 100 installs  i get a runtime error 0 and my.does not even run. i have tried my solutations to no avail. How can i determine thu vb6 code if a firewall is blocking my app ?
0
Comment
Question by:isnoend2001
  • 2
4 Comments
 
LVL 5

Assisted Solution

by:KiasChaos83
KiasChaos83 earned 250 total points
ID: 33434494
You can't really tell if a firewall is blocking your connection.

The problem is that a blocked connection has the same behaviour as a connection where the computer doesn't exist. Does that make sense? If you get blocked by a firewall, the firewall doesn't let you know that you were blocked.. it just ignores your request completely.
0
 
LVL 4

Accepted Solution

by:
CarlvanEijk earned 250 total points
ID: 33434585
You could use TCPveiw to work out what ports are being used by your app, and work backwards from there: http://technet.microsoft.com/en-us/sysinternals/bb897437.aspx

If it's the local firewall, you can identify the ports/aps and add specific tcp/udp rules. If you're supplying the application for many machines on the network you can configure the windows firewall via Group Policy
http://technet.microsoft.com/en-us/library/bb490626.aspx

Furthermore, once you've identified the ports you can apply these same rules to the enterprise firewalls, either yourself or via the local sysadmin person. The settings will be specific to the flavour of firewall, so I can;t help with specifics.

Once you've worked all that out, you could add some sort of built in post install test to check if the ports are open and popup a readme for how to resolve firewall issues......
0
 

Author Closing Comment

by:isnoend2001
ID: 33434687
Thanks guys have found it is not the firewall as the user told me his computer name. Then looking at the emails i get on first install i was able to determine that indeed i did get
an email for this user. I usually get about 20 a day with users permission telling me the users pc name os, etc and can never determine who the user is.
0
 
LVL 4

Expert Comment

by:CarlvanEijk
ID: 33435124
your bad ;)
0

Featured Post

Announcing the Most Valuable Experts of 2016

MVEs are more concerned with the satisfaction of those they help than with the considerable points they can earn. They are the types of people you feel privileged to call colleagues. Join us in honoring this amazing group of Experts.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

I’ve seen a number of people looking for examples of how to access web services from VB6.  I’ve been using a test harness I built in VB6 (using many resources I found online) that I use for small projects to work out how to communicate with web serv…
Introduction While answering a recent question (http://www.experts-exchange.com/Q_27402310.html) in the VB classic zone, I wrote some VB code in the (Office) VBA environment, rather than fire up my older PC.  I didn't post completely correct code o…
Get people started with the process of using Access VBA to control Excel using automation, Microsoft Access can control other applications. An example is the ability to programmatically talk to Excel. Using automation, an Access application can laun…
This lesson covers basic error handling code in Microsoft Excel using VBA. This is the first lesson in a 3-part series that uses code to loop through an Excel spreadsheet in VBA and then fix errors, taking advantage of error handling code. This l…

828 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question