Failed to bind UDP socket

[SPlatten]

@KroMignon This is my code:

    for( const QHostAddress& address : QNetworkInterface::allAddresses() )
    {
        if ( address.protocol() == QAbstractSocket::IPv4Protocol )
        {
            QString strAddress(address.toString());
            if ( !(strAddress.compare("localhost") == 0
                || strAddress.compare("127.0.0.1") == 0) )
           {
                return QHostAddress(address);//"10.186.53.82");
            }
        }
    }
    return QHostAddress();

I intentionally don't want to use "localhost" or "127.0.0.1", so the IP returned is most definitely from a local adapter.

[KroMignon]

@SPlatten said in Failed to bind UDP socket:

I intentionally don't want to use "localhost" or "127.0.0.1", so the IP returned is most definitely from a local adapter.

Just as side note: you could check this with address.isLoopback().

Can you show how the error message is generated?

It is strange, because QNetworkInterface::allAddresses() should only returns IP addresses from network interfaces which are up/active.

[SPlatten]

@KroMignon The only information I have is from a screenshot taken from the screen of the guy running the application which shows exactly what I posted initially:

UDP on IP: 169.254.50.150 port: 30119
Failed to bind UDP socket:  The address is not available

[KroMignon]

@SPlatten said in Failed to bind UDP socket:

The only information I have is from a screenshot taken from the screen of the guy running the application which shows exactly what I posted initially:
UDP on IP: 169.254.50.150 port: 30119
Failed to bind UDP socket: The address is not available

But this message has been generated with your application, or did I miss understood something?

[SPlatten]

@KroMignon , only the first line comes from my application. I assume the second line is from a Qt object.

[JonB]

@SPlatten
I don't think this will be a Qt issue. Try Googling Failed to bind UDP socket: The address is not available, you get a few hits worth reading through?

[SPlatten]

@JonB , @KroMignon , sorry, I found the message, its displayed when:

    const QHostAddress local(localAddress());   
    //The server is also going to listen for UDP data
    qinf() << QString("UDP on IP: %1 port: %2").arg(local.toString())
                                               .arg(SckServer::msuint16PortUDP);
    if ( !this->bind(local, SckServer::msuint16PortUDP, QUdpSocket::ShareAddress |
                                                        QUdpSocket::ReuseAddressHint) )
    {
        qcrt() << SckServer::tr("Failed to bind UDP socket: ").toLatin1().data()
               << this->errorString();
        exit(EXIT_FAILURE);
    }

localAddress() contains the source I posted earlier, now with the modification:

QHostAddress SckServer::localAddress()
{
    for( const QHostAddress& address : QNetworkInterface::allAddresses() )
    {
        if ( address.protocol() == QAbstractSocket::IPv4Protocol &&
             address.isLoopback() != true )
        {
            return address;
        }
    }
    return QHostAddress();
}

[KroMignon]

@SPlatten said in Failed to bind UDP socket:

I assume the second line is from a Qt object.

This error message is when trying to use an local IP address which is not available.
For me, it looks like your system has IP configuration issues.
Do your system have multiple network interfaces?
Is this IP configured on several interfaces?

[SPlatten]

@KroMignon , my system has no issues, its another system which a colleague is trying to run the application on. I think its down to configuration, but I cannot determine why because I don't have access to the system.

[KroMignon]

@SPlatten said in Failed to bind UDP socket:

my system has no issues, its another system which a colleague is trying to run the application on. I think its down to configuration, but I cannot determine why because I don't have access to the system.

"Your system" == "the not working system"

I had understood that it was not on development machine ;)

Perhaps your colleague could send you the output of: ipconfig /all > ipconfig.txt (I assume it is a Window system)
So you could check the IP configuration of the machine.

This would be my way to understand/solve the issue.

[SPlatten]

@KroMignon , first line of my post:

"The application works fine on the development system, however I have sent to application to another for testing and the problem is when trying to execute the application"

The development machine is my system. And your instruction is exactly the content I sent to my colleague hours ago, the response came back with very little output. Windows 10. He is now waiting for IT to take a look at the computer.

[KroMignon]

@SPlatten said in Failed to bind UDP socket:

"The application works fine on the development system, however I have sent to application to another for testing and the problem is when trying to execute the application"

Yes, I have read this.

• I have understood that it works your PC.
• I have understood that is does not work on your colleague PC

What I say, is that, IMHO, the problem is linked to "not working PC" network configuration.
That's all what I say, but it is only a feeling. This is why showing the network configuration could be a key to understand what's going wrong.

It could also be a security issue, maybe the account used to start application have no right to use this interface.

[SPlatten]

@KroMignon Thank you, waiting to hear back from colleague.

[Pablo J. Rogina]

@SPlatten said in Failed to bind UDP socket:

UDP on IP: 169.254.50.150

It looks like the NIC in that machine couldn't get an IP assigned from the DHCP server. See this post for more details.

[KroMignon]

@Pablo-J-Rogina said in Failed to bind UDP socket:

It looks like the NIC in that machine couldn't get an IP assigned from the DHCP server.

Good catch!

[SPlatten]

@Pablo-J-Rogina thank you, will look into it.