3.1.3 SDLNet_Quit

void SDLNet_Quit()

Shutdown and cleanup the network API.
After calling this all sockets are closed, and the SDL_net functions should not be used. You may, of course, use SDLNet_Init to use the functionality again.

SDLNet_Quit(); // you could SDL_Quit(); here...or not.

See Also:
3.1.2 SDLNet_Init