Re: [DNSOP] Last Call: <draft-ietf-dnsop-5966bis-04.txt> (DNS Transport over TCP - Implementation Requirements) to Internet Standard

[神明達哉 <[e-mail]>]

At Mon, 23 Nov 2015 21:37:48 +0530,
Mukund Sivaraman <[e-mail]> wrote:

> While looking at a bug last week in an implementation of 5966bis and
> AXFR, I found that there's no explicit mention of AXFR and out-of-order
> replies. AXFR replies [RFC 5936] can arrive in several messages over
> TCP. While 5966bis speaks only about re-ordering replies and not
> individiual messages (and so, is not incorrect), I feel that explicitly
> describing ordering in the AXFR case would avoid confusion.
>
> It seems that AXFR messages would have to be sent in order to avoid
> confusion at the client about when a transfer correctly completed
> vs. when it timed out. While they can be multiplexed with other DNS
> messages, the individual messages of a single transfer must not be sent
> out of order.

I'm not sure if I understand the concern...do you mean, for example,
if an AXFR consists of the following 3 messages:

Message1: beginning SOA and some RRs
Message2: some intermediate RRs
Message3: some more intermediate RRs
Message4: some more RRs and ending SOA

the client side of AXFR receives them in the order of, e.g., Message2,
Message3, Message4, and then Message1?  That is, Message1 is not
necessarily sent/received first and/or Message4 is not necessarily
sent/received last?

--
JINMEI, Tatuya