In message <93f32648fd67ae6abac47...@jck-hp8200.jck.com>, John C Klensin writes
:
> Hi.
>
> I have a few questions that I don't want to clutter the IETF
> list about but about which I would hope DNS experts, especially
> DNS root operations experts, would step in if they have
> opinions. IESG copied only for the record. I want to stress
> that these are questions: I may know enough to ask them but
> can't even competently speculate on the answers.
>
> The new specification proposes what is, in essence, a
> convention. If an SMTP-Sender (to use the original and very
> precise terminology), while doing the required lookup for an MX
> RR, encounters
>
> IN MX 0 .
>
> it is expected to abort the message-sending process -- no
> further lookups, not connection attempts, no queuing.
>
> At least in the near term, some SMTP Server ("MTA")
> implementations will conform to that rule (many already use it)
> and some won't. For the latter, they will presumably do what
> the SMTP specs say to do. In summary, that is to look up the
> address(es) associated with the root and try to open a mail
No. Lookup the address _at_ _the_ _root_. This is _not_ the
addresses of the root servers.
> connection to one of them. When that connection fails
> (presumably times out), the SMTP server may decide to try more
> (or all) of the other addresses. When all of those it chooses
> to try fail, it is then required to queue the message, retrying
> the process (potentially to all 13 root servers) at regular
> intervals for an extended period of time.
What connection? There are no addresses records at "." so the MTA
returns a NDN.
Mark
--
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742 INTERNET: ma...@isc.org
_______________________________________________
DNSOP mailing list
DNSOP@ietf.org
https://www.ietf.org/mailman/listinfo/dnsop
