Lets assume I need to send some ASCII data to a Ethernet to Serial Device on a network. I know it's IP and Port Number. No problems there.
Now I also need to wait for a reply from the device to say if it's happy with what I've sent it. Again - not such a chore.
HOWEVER.
The server running this application has 4 network
cards in it. Each network card is connected to a separate VLAN. The TCP/IP settings for each network card (Windows 2003) specifies only 1 gateway address on one of the
cards. So far so good.
Assuming that the network has been set-up correctly my outbound connection to SEND data will be sent via the gateway and make a connection to the remote machine.
Now lets assume I want a separate
thread to handle the reply coming back. I know the port number that I am listening on - but do I need to know the interface (network card) that will be receiving the reply. I know it's the one that the gateway address is specified, but my program does not ? Does that matter ? Do I need to listen against a specific interface ?
Thanks
Dave