Re: v6ops-v6onbydefault: link-locals and AI_ADDRCONFIG

[Pekka Savola <pekkas@netcore.fi>]

On Mon, 3 Nov 2003, Colm MacCarthaigh wrote:
> > DNS is a specific lookup service.  not a random one that just might happen
> > to be around.
> 
> NIS is a specific lookup service, as is WINS, and well I could go on ...
> DNS may be more standardised, more widely-deployed and frankly - more
> tasteful, but it is no more specific. It's not the only show in town :)
> 
> I don't mean to be facetious here, of course I regard DNS as the "standard"
> name to number resolver, but I'm a long long way from thinking it should 
> be the only means allowed for applications to resolve names.

My personal experience is that the lookup mechanisms are rarely fully
equivalent/replaceable.  They give different kinds of results.  
/etc/hosts and DNS are (typically) pretty close to each other, but if you
pluck in e.g. WINS, the names it'll give you are typically entirely
different (starting from the format) from those learned from DNS.

I'd expect similar inconsistancies if queries were done using LLMNR or 
ICMP Node Information Queries.

The important point here is who configures the names to be looked up.  
Looking them up e.g. in LDAP would probably yield similar results than
lookup up from the DNS (as they're very probably configured by the same
entity) -- but asking from the node itself what it thinks its name is is
*very* likely to yield different results than one would get asking his
network administrator..

I think typically we have been interested of the latter, that is, what the 
network administrator of a node thinks a node's name is (and NOT what the 
node or its user thinks!)

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