On Tue, Jul 11, 2000 at 12:19:52PM -0400, der Mouse wrote:
> > I have 2 questions related to BSD sockets programming:
> 
> > 1.How can I explicitly specify outgoing interface when sending packet
> > using BSD sockets ?
> 
> I don't think you can, though there are two things you can do that may
> come close.  You can bind() the socket before doing a connect(), to
> specify the address of your end of the connection; however, unless you
> do something further, the usual routing mechanisms will still be
> applied to choose the outgoing interface based on the peer address.
> You can also turn on the SO_DONTROUTE socket option with setsockopt(),
> but I suspect that will not work unless the peer is on a
> directly-connected network.
> 
> > 2.How can I send limited broadcast (255.255.255.255) using BSD
> > sockets ?
> 
> It doesn't work to use sendto() with a sockaddr_in holding that in its
> sin_addr?  (I've never tried it myself.)
> 
> > How can I specify outgoing interface for such broadcast ?
> 
> Good point.  Thinking about it now, I'm not convinced it's possible,
> and if it is, it probably goes out all interfaces.  You may have to use
> bpf rather than a simple socket. :-P

I vaguely remember I fixed, or at least considered to fix, this, so that it
should be possible now in the same way as you specify a outogoing interface
for multicast packets.

Regards,
	-is