[Sugar-devel] Notes on service discovery XS/XO

[david at lang.hm]

On Wed, 22 Apr 2009, Martin Langhoff wrote:

> On Wed, Apr 22, 2009 at 2:46 AM,  <david at lang.hm> wrote:
>> I believe this is exactly what has been done over the last few years in the
>> DNS server/DNS cache software. they used to accept extra responses like you
>> are trying to make, but nowdays they don't.
>
> As everyone pointed out, I was wrong about plain client resolvers. My
> understanding of the tightening of the rules is that resolving servers
> -- which could end up with a poisoned cache -- now apply strict rules
> to what they accept in the additional section.
>
> But it may well be that things have been tightened further and clients
> completely ignore it. I got the "ignore unrelated / non authoritative
> entries" memo, maybe there's been an "ignore everything" one.

as noted elsewhere in this thread, clients don't cache things, so the only 
benifit of sending the extra things is if you are running a cache.

since you are able to control what software gets used on the XO, you can 
make the DNS cache be one that applies rules that allow you to send the 
extra stuff that you want. but I think that is probably not a great idea 
as it can break if that package gets changed upstream to follow a 
different set of rules.

David Lang