On Sun, 2021-06-06 at 20:26 -0400, Martin Peach wrote:
If you have a [udpreceive 9898] as your 'server' it will receive from anywhere on port 9898. So you can take the sender's ip and port from the latest incoming message (route 'from' at the second outlet) and use them to set the address and port of a single [udpsend] for the reply. There is no connection in udp so you need to add metadata in your datagrams for routing and so forth.
Again, this does not work. The socket on the client side will only accept packets originating from the port it has sent packets to, but [udpsend] on the server cannot use this port as bind port, because it is already occupied by [udpreceive]. To put this into telephone analogy: When you call someone, you expect a third party to be prohibited from shouting into your call, and you expect to hear only the party you called.
The only solution to this is to use the same socket for both sending and receiving, as Christof already suggested.
Roman