How can I connect client to server without knowing there IP's?

[mismael85]

Hi Everybody,

How can I connect Client and server without knowing there IP's?

[squidge]

You could send a broadcast UDP packet from the client which the server answers with it's IP address and port number? Or perhaps the server connects to the client once it received such a packet?

[Santosh Reddy]

No, you cannot connect without knowing IP and port. What you can do is to find out a way to know the Server IP, either use DNS, or broadcast to find out IP

[Markus_AC]

That thread exactly meets my qustions. Thanks, as far. But three further questions:
1) Is it possible to open a QUdpSocket (for Broadcasting and searching for new devices) as well as aQTcpSocket (for data exchange)?
2) In my system I have two network interfaces. How do I select the broadcast for just one interface?
3) How do get the IP-Adress of the sender, when I have received a broadcast message?

[Markus_AC]

I figured out tzhe answer to my qustion #3:

QHostAddress sender;
quint16 senderPort;
 
udpSocket->readDatagram(datagram.data(), datagram.size(), &sender, &senderPort);

QHostAddress sender;
quint16 senderPort;

udpSocket->readDatagram(datagram.data(), datagram.size(), &sender, &senderPort);

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But still I don't know what to do with my qustions #1 and #2.

Can someone help?