Re: v6ops-v6onbydefault: link-locals and AI_ADDRCONFIG

[Pekka Savola <pekkas@netcore.fi>]

On Wed, 29 Oct 2003, Jun-ichiro itojun Hagino wrote:
> 	d) obsolete AI_ADDRCONFIG.  AI_ADDRCONFIG semantics is too vague, and
> 	way too difficult to specify (for instance, if you have IPv6 global
> 	unicast address and no route, is it configured?).  also, even without
> 	AI_ADDRCONFIG programs work just fine (socket(2) or connect(2) will
> 	issue the right error).

Agreed, that might be one option.

Without the on-link assumption, the default route case should be rather
simple, though.  You'd only have to look at the addresses.

IMHO, without the on-link assumption, AI_ADDRCONFIG could help a lot in
dual-stack deployments where IPv6 connectivity is not yet enabled.  

Of course, properly written apps would most probably also work there, but
some apps are not properly written, but:

 - there are really misbehaving DNS servers out there, which jeopardize 
your IPv4 service if you query for AAAA's, and
 - if you have no IPv6 address, you'll waste a roundtrip or two in AAAA 
queries
 - maybe other considerations we haven't figured out / thought out yet.

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