Strange failure on XN--MGBA3A4F16A.

[John R Levine]

In article <alpine.LRH.2.21.1905161448390.8487 at bofh.nohats.ca>,
Paul Wouters via Unbound-users <paul at nohats.ca> wrote:
> A restart with enabled verbosity to see what's going on, of
> course worked like a charm :/
> 
> Note the TTL is pretty short (1440, did someone confuse MTU for TTL?)
> 
> Manual checking:

Oh, wait, the servers for .ir and for .XN--MGBA3A4F16A are different.

Start via local root
$ drill @127.12.12.12  XN--MGBA3A4F16A. soa
;; ->>HEADER<<- opcode: QUERY, rcode: NOERROR, id: 63506
;; flags: qr rd ; QUERY: 1, ANSWER: 0, AUTHORITY: 2, ADDITIONAL: 2
;; QUESTION SECTION:
;; XN--MGBA3A4F16A.	IN	SOA

;; ANSWER SECTION:

;; AUTHORITY SECTION:
XN--MGBA3A4F16A.	172800	IN	NS	a.nic.ir.
XN--MGBA3A4F16A.	172800	IN	NS	ns.irnic.ir.

$ drill @193.189.123.2 XN--MGBA3A4F16A. soa
; timeout

$ drill @193.189.122.83 XN--MGBA3A4F16A. soa
;; ->>HEADER<<- opcode: QUERY, rcode: SERVFAIL, id: 65073
;; flags: qr rd ; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;; XN--MGBA3A4F16A.	IN	SOA

I guess that explains it.  Not my problem. But where'd Google's
answers come from?  The NS I'm getting from my local root match the
ones from the real root and what's here:
https://www.iana.org/domains/root/db/xn--mgba3a4f16a.html

$ drill @8.8.8.8 XN--MGBA3A4F16A. ns
;; ->>HEADER<<- opcode: QUERY, rcode: NOERROR, id: 56461
;; flags: qr rd ra ; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;; XN--MGBA3A4F16A.	IN	NS

;; ANSWER SECTION:
XN--MGBA3A4F16A.	1439	IN	NS	b.nic.ir.
XN--MGBA3A4F16A.	1439	IN	NS	a.nic.ir.
XN--MGBA3A4F16A.	1439	IN	NS	ir.cctld.authdns.ripe.net.

$ drill @8.8.8.8 XN--MGBA3A4F16A. soa
;; ->>HEADER<<- opcode: QUERY, rcode: NOERROR, id: 25896
;; flags: qr rd ra ; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;; XN--MGBA3A4F16A.	IN	SOA

;; ANSWER SECTION:
XN--MGBA3A4F16A.	1439	IN	SOA	ns1.nic.ir. info.nic.ir.
2019051622 14400 1800 604800 1440

R's,
John
-- 
Regards,
John Levine, johnl at iecc.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly