why can't I open a port on Win 7? is it the app's fault?

Question

I am having problems opening a port from one Windows PC on my local network.

On Windows 7 computer ("Computer A") I running Calibre, an ebook management program that has something called an "ebook content server" . In essence, it serves via the web a content catalog.

From Computer A, I can access the content server on localhost. ie. http://127.0.0.1:8787 calls up the content server successfully. With ipconfig I have confirmed that its local IP address is 192.168.1.106 From Computer B (a Vista Machine) I can ping 192.168.1.106 I have tried opening/editing a port in the Windows Firewall several times.

In Windows firewall --> Allowed Programs in Control Panel, I see a listing for Calibre (with both Home/Work and PUblic checked) In details, I see Name: Calibre, Port Number 8787, Protocol TCP

If I use the Advanced Security configuration screen for the firewall, I created an Inbound Rule on Computer A for Calibre (with the settings I indicated).

If I run this command line on Computer A, I see:

netstat -a -n

  TCP    0.0.0.0:554            0.0.0.0:0              LISTENING
  TCP    0.0.0.0:664            0.0.0.0:0              LISTENING
  TCP    0.0.0.0:2869           0.0.0.0:0              LISTENING
  TCP    0.0.0.0:3306           0.0.0.0:0              LISTENING
  TCP    0.0.0.0:5357           0.0.0.0:0              LISTENING
  TCP    0.0.0.0:6570           0.0.0.0:0              LISTENING
  TCP    0.0.0.0:6580           0.0.0.0:0              LISTENING
  TCP    0.0.0.0:8787           0.0.0.0:0              LISTENING
  TCP    0.0.0.0:10243          0.0.0.0:0              LISTENING

 TCP    192.168.1.106:63020    74.125.227.51:80       TIME_WAIT
 TCP    [::]:80                [::]:0                 LISTENING
 TCP    [::]:135               [::]:0                 LISTENING
 TCP    [::]:443               [::]:0                 LISTENING
 TCP    [::]:445               [::]:0                 LISTENING
 TCP    [::]:554               [::]:0                 LISTENING
 TCP    [::]:2869              [::]:0                 LISTENING
 TCP    [::]:5357              [::]:0                 LISTENING
 TCP    [::]:6570              [::]:0                 LISTENING
 TCP    [::]:6580              [::]:0                 LISTENING
 TCP    [::]:10243             [::]:0                 LISTENING
 TCP    [::]:49152             [::]:0                 LISTENING
 TCP    [::]:49153             [::]:0                 LISTENING
 TCP    [::]:49154             [::]:0                 LISTENING
 TCP    [::]:49155             [::]:0                 LISTENING
 TCP    [::]:49170             [::]:0                 LISTENING

And lots of other junk, but this seems relevant, I see port 80 is open (I run xampp apache web server for windows on Machine A) This is the only time I see port 8787 referenced from the netstat commmand.

From Windows Computer B, I can, ping 192.168.1.106 and even view http://drupal.local (on Computer A) and http://192.168.1.106/ (which goes to the Xampp config screen on Computer A).

But I cannot access via Computer B htttp://192.168.1.106:8787 or htttp://computerhosta:8787

So what is going wrong? Is this a problem with the Calibre application or have I incorrectly opened the port? What things could possibly interfere with the opening of this port?

On a sidenote, I have tried using telnet from Computer B to see if port 80 or 8787 is open for 192.168.1.106. I get no reply for either one.

Thanks.

Answer 1

Ok, I think I solved the problem for now.

I installed calibre on Computer B (Vista 64) and enabled the Calibre Content Server. It prompted me for an "Add an exception for Calibre" and I accepted. From Computer A I could access calibre server, no problem.

That led me to reexamine how I set up things on Computer A (Win 7).

First, on I deleted all references to Calibre in Windows Firewall --> Allowed Programs.

I verified everything was removed on the Advanced Settings screen.

Then I turned on Calibre, the Firewall prompted me to add an exception, which I did.

I checked on public and private network, but later I realized that I could turn off Public network, and it would still work.

One thing I noticed that in allowed programs there were 2 separate entries for Calibre. Either 1 of them was not checked, or the first entry had public checked but not private and vice versa. Ultimately, I made sure there was a check mark for both entries and I made sure that private was checked for both. (The public no longer wasn't necessary).

(I rebooted for unrelated reasons, so that MIGHT be necessary though unlikely).

Problem fixed.