bind socket to network interface

Question

How can I bind a socket to a particular network interface? I tried using setsockopt on server side, but the clients can still access the service through both et

Answer 1

The only way you can do it is as you mention -

by setting the particular IP address using serv_addr.sin_addr.s_addr

You can't do it without knowing the address to bind to.

You can use ioctls to determine the current IP address if you need, though there may be a cleverer way to do this these days - I've not done much in modern Linux distros lately.