Re: receiving and sending packets to 255.255.255.255

[Dennis Ferguson <dennis.c.ferguson%gmail.com@localhost>]

On 13 Dec, 2011, at 12:10 , Edgar Fuß wrote:

> Two questions regarding the all-ones aka limited-broadcast aka 
> INADDR_BROADCAST address:
> 
> 1. Is ist true/documented that I only receive broadcasts directed to that 
> address if I listen on INADDR_ANY aka 0.0.0.0?
> 
> 2. When I want to send to that address, how do I specify the interface to 
> send on (or network to send to)? I thought that was determined by address the 
> sending socket was bound to, but that seems not to be true.

For 2. try the IP_MULTICAST_IF socket option.  I think sending to 
255.255.255.255
works the same as sending to 224.0.0.1 (or, at least, it should work the same
way because it is the same problem).

Dennis Ferguson