Straw poll - All-interface broadcast/multicast

[Barney Wolff]

On Tue, Nov 18, 2003 at 01:02:00PM +0000, Bruce M Simpson wrote:
> On the subject of hacking the network stack to output broadcast/multicast
> datagrams on all appropriate interfaces:-
> 
>  Who would like a switch to do this in the kernel?
> 
>  Who would be happier with a userland convenience function to do it?
> 
>  Who would rather roll their own?
> 
> I have a diff in the works to do this, 'just for the heck of it', but I am
> very wary of putting anything in the stack 'just for the heck of it' as
> the current IP_ONESBCAST workaround strikes me as 'good enough'.

Some questions, because I'd like to be an educated voter.

1.  How does multicast routing work now?  Presumably something takes a
mcast packet and sends it out to every interface behind which some host
has indicated group membership.  Is this kernel or userland?  Does it
work at all?

2.  How is "appropriate" defined - by administrator choice or by some
inherent property of the interface hardware type?

3.  How do other OS's do it, if at all?

4.  How will this interact with IPv6?  IPsec?

Thanks,
Barney

-- 
Barney Wolff         http://www.databus.com/bwresume.pdf
I'm available by contract or FT, in the NYC metro area or via the 'Net.