[radvd-devel-l] Wildcard Interface Addresses

Pekka Savola pekkas at netcore.fi
Mon Feb 11 08:22:45 EST 2008

On Mon, 11 Feb 2008, Norman Rasmussen wrote:
> Hrm, I had enabled UnicastOnly, which disabled unsolicited advertisements.
> If I disable UnicastOnly, then the RA's are sent and Vista configures the
> extra IP's.  With 1.1 it complains that I should be using UnicastOnly
> because the interface can't broadcast, but if I enable it, then the RA's are
> not sent.
> This says that Vista expects unsolicited RA's over it's ppp link:
> http://blogs.technet.com/rrasblog/archive/2006/12/15/vista-how-pppv6-support-works.aspx

I don't see the word "unsolicited" in this article.  As a matter of 
fact, to the countrary -- in 4) and 5) it says that Vista will send a 
Router Solicitation, and the router will respond with an RA (i.e., a 
solicited advertisement).  So "UnicastOnly" should work OK with Vista 
as well.

AFAIR, radvd will not re-advertise the RA, however, so Vista might 
forget the prefix/route information transmitted in the original RA 
after a while if it doesn't re-send the RS.

So, while UnicastOnly should work at least initially, there might be 
problems after the RA's lifetimes expire.

On the other hand, you could just try adding BROADCAST and MULTICAST 
flags on the interface and see if it works, or alternatively just 
ignore radvd's warning about possibly needing UnicastOnly (if it's 
working fine).

> I was advertising fe80::/64 and 2001:618:400:6f39::/64. radvd wasn't
> transmitting the RA unless I disabled UnicastOnly, then the new 1.1 version
> complains when I enabled it, and the interface doesn't support broadcast.  I
> need a unsolicited unicast option :-)

I'd remove fe80::/64 because it's ignored on the recipient side 
anyway.  But it's probably not causing problems.

Are you saying that with 1.0 there is no complaint but with 1.1 there 
is?  I don't think there were code changes here, so if you think this 
is the case, I'd like to see some debug log (e.g., radvd with 
arguments like '-d 5 -m stderr')

Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings

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