Why isn't my application receiving broadcast packets?

Question

I have written a Qt application that listens for UDP broadcast packets on the network interface p2p1. I have installed the application in Fedora 17 i386 in a VirtualBox VM. For some reason, the application is not receiving any broadcast packets that I am sending.

I installed and ran Wireshark and verified that the broadcast packets are indeed arriving on p2p1:

Does anyone have any idea why the application (which is listening for UDP packets on port 41720) isn't receiving any of the packets? Some security setting or something?

Answer 1

The following set of steps were able to resolve the problem:

1. Open a terminal and type:
   

   system-config-firewall

2. Enter your password if prompted.
3. Click "Other Ports" on the left-hand side:
   
4. Click the "Add" button on the right-hand side:
   
5. Check "User Defined" and enter the values below:
   
6. Click "OK" and then click the "Apply" button in the toolbar:
   
7. If you are warned that selecting "Yes" will override any existing firewall configuration, you may safely click "Yes".

_{Note: the above instructions were copied from this page, which I am the author of.}