#982 IpMulticastTtl configuration parameter does not work

[Adriano Marto Reis]

I am trying to change the multicast group and the TTL of the UDP packages sent by the application. The intent is to enable BeeBEEP to find peers in different subnets (the network is properly configured to support that). I can change the multicast group without any issues, but I can't change the TTL.

I am using the following RC file. The desired TTL value is presented on the network configuration page as expected. However, inspecting the packets using WireShark show that the TTL is always 1.

[BeeBEEP]
MulticastGroupAddress="224.1.1.100"

[Network]
UseDefaultMulticastGroupAddress=false
IpMulticastTtl=64

BeeBEEP version 5.8.5

[Adriano Marto Reis]

Hi,

I had a quick look at the problem. Although I can't find anything wrong with the code, I found quite a few reports that QUdpSocket does not behave well when it is not bound to an interface or address. So I modified the code so we use the same socket for sending and receiving. That was enough to make the QUdpSocket accept the TTL value defined in IpMulticastTtl.

I would create a pull request myself, but I could find out how to do it in the BeeBEEP project. So I uploaded a diff file.

Cheers,
Adriano.

[Marco Mastroddi]

Thank you very much Adriano. In these days I worked hard, so I will check the problem in the weekend. Thank you for the patch.... I will merge it as soon as possible. I'm curious about the problem in QUdpSocket... because in the first release of Broadcaster I used only one socket... then I used 2 udp sockets (sender and receiver) but I don't remember why I change it...