> >So, if NSI wants to add more servers for .com/.net/.org it isn't going to
> >be able to do so, at least not from the current root system, at least
> >without violating that part of the specification.
>
> They can have as many servers as they want, so long as no individual
> response from the roots is more than 512 bytes. It'd be pretty simple
> to twiddle BIND to rotate through the list giving each requester 12
> servers chosen from the total set so that each server appears in
> `roughly equal numbers of responses.
>
> This code may already be in place. I know that AOL and some other
> large sites rotate the answers they give to queries for MX servers and
> for things like the ICQ master server.
You are right. Yes, the DNS spec only demands that there be no more than
twelve servers listed in the packet. But I'm not at all sure what
happens, however, as a user's intermediary server learns that a TLD has
more than 12 servers. Those intermediary servers would have to also limit
their responses to listing only a subset of what they know.
(All in all the 512 byte restriction is a pain, and an obsolete one.)
--karl--
