Path: utzoo!attcan!uunet!lll-winken!lll-lcc!ames!pasteur!ucbvax!ANDREW.CMU.EDU!ddp+ From: ddp+@ANDREW.CMU.EDU (Drew Daniel Perkins) Newsgroups: comp.protocols.tcp-ip Subject: Re: default broadcast address Message-ID: <0Wrc7By00UoJE0kXZO@andrew.cmu.edu> Date: 15 Jul 88 22:06:05 GMT References:Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 18 > *Excerpts from ext.in.tcp-ip: 12-Jul-88 Re: default broadcast address* > *Charles Hedrick@princeto (991)* > I don't know whether this is what actually happens in > 4.3BSD, but I know what *should* happen. The application should use > net.subnet.-1. > That way they can all be -1 or 0, etc., but your application can still > specify which interface to use. I don't think this is appropriate for all implementations. The ip layer shouldn't be second guessing the application. Some applications may want to send to -1 and some may want to send to net.subnet.-1. 4.3BSD is broken because it doesn't allow an application to send to -1 yet still specify which interface to use. It could use some out-of-band indication such as bind() or an ioctl(). I.e. if you bind() to the address of a particular interface (vs. INADDR_ANY) and send to -1 it could route the packet to the interface of the address to which you are bound. Drew