A machine has 2 NICs. Which one will be utilized when connecting to a socket?

Question

Suppose I create a very simple socket connection, how can one programatically:

1. Find out what interface (ip address / NIC) is being used.
2. Force the ot

Answer 1

a. After a connection is established, most socket APIs have a call for something like "getLocalAddress" that will tell you the interface that the OS selected for you.

b. Similarly, after a socket is created but before a connection is established, most socket APIs have a call to bind the socket to a local address and/or port.