At 02:58 PM 1/8/2002 +0000, David Laight wrote:
> > >         when there's no IPv4 address assigned to the multicast outgoing
> > >         interface (specified by setsockopt), kernel made panic.  i've
> > > committed
> > >         the following change to avoid the kernel panic.  historic 
> behavior
> > >         was to use 0.0.0.0 as source.
> > >         my question is, which behavior look better?  do any of you know
> > >         apps that assumes "0.0.0.0 as source" behavior?
> > >
> > >         reasoning for using 0.0.0.0 as source:
> > >                 "0.0.0.0 as source" is legal only while the interface is
> > >                 being initialized (RFC1122 p30), therefore, if 
> there's some
> > >                 user program that uses multicast for interface
> > > initialization,
> > >                 they want the behavior.
> > >         reasoning for forbidding packet transmission:
> > >                 IP source address must be one of the interface 
> addresses that
> > >                 belong to outgoing interface (RFC1112 p6).  if 
> there's none,
> > >                 we shouldn't send packet.
> >
> > If NetBSD supported unnumbered interfaces, then the proper thing would 
> be to
> > use the parent interface's primary address.  If the the parent's primary
> > address
> > wasn't set, then you'd default back to the router-id of the system.  If no
> > router-id was set, you'd return EADDRNOTAVAIL.  You would never use 
> 0.0.0.0 as
> > the source address.
>
>Why not?
>It's about the best address for the dhcpc request...

Reread.  We aren't talking about DHCP here.

-- 
Matt Thomas               Internet:   matt@3am-software.com
3am Software Foundry      WWW URL:    http://www.3am-software.com/bio/matt/
Cupertino, CA             Disclaimer: I avow all knowledge of this message