(usagi-users 03468) Re: IPv6 Multicast question - connect fails

[Stig Venaas <Stig.Venaas@xxxxxxxxxx>]

On Tue, Aug 09, 2005 at 05:01:35PM +0200, Bas Vermeulen wrote:
[...]
> The connect will fail with EADDRNOTAVAIL if there are only link-local
> addresses on the interfaces. If there is a global IPv6 IP on the link,
> things work. I am trying to find out why.

I haven't looked at your code, but I have done some tests with ping
(and strace). With only link-local address I get:

adiamante ~ # ping6 -I eth0 ff03::1
connect: Cannot assign requested address

for scopes larger than 2. This is EADDRNOTAVAIL. For scope 2 it works.

I don't think this behaviour is unreasonable. It should maybe be possible
to send to global multicast group on the local link, but do you see a
need for that? To send past the local link you can't use link-local
source address due to RPF checks. And it would IMO be a bad idea anyway.

Stig