xn--y9a3aq TLD DNSSEC Outage: 2018-12-06

Date: December 6, 2018

Overview

This page gives some details on the xn--y9a3aq (Armenia) TLD DNSSEC outage on December 6, 2018.

Verisign's DNSSEC Debugger

Verisign doesn't archive test results, unlike DNSViz. So here's a screenshot I took on December 6, 2018:

xn--y9a3aq dnssec outage

Timeline / DNSViz

Google Public DNS: with and without DNSSEC

DNSSEC can be disabled in queries via the CD (checking disabled) bit. Let's compare DNS queries with and without DNSSEC. With DNSSEC, DNS queries result in SERVFAIL:

$ dig +dnssec ns xn--y9a3aq. @8.8.8.8

; <<>> DiG 9.4.2-P2 <<>> +dnssec ns xn--y9a3aq. @8.8.8.8
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 61024
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags: do; udp: 512
;; QUESTION SECTION:
;xn--y9a3aq. IN NS

;; Query time: 50 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Thu Dec 6 17:24:01 2018
;; MSG SIZE rcvd: 39

You have to disable DNSSEC to make DNS work:

$ dig +cd ns xn--y9a3aq. @8.8.8.8

; <<>> DiG 9.4.2-P2 <<>> +cd ns xn--y9a3aq. @8.8.8.8
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 64574
;; flags: qr rd ra cd; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;xn--y9a3aq. IN NS

;; ANSWER SECTION:
xn--y9a3aq. 21599 IN NS sns-pb.isc.org.
xn--y9a3aq. 21599 IN NS fork.sth.dnsnode.net.
xn--y9a3aq. 21599 IN NS ns-pch.amnic.net.
xn--y9a3aq. 21599 IN NS ns-cdn.amnic.net.
xn--y9a3aq. 21599 IN NS ns-pri.nic.am.

;; Query time: 37 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Thu Dec 6 17:24:01 2018
;; MSG SIZE rcvd: 165

drill trace

Since DNSSEC contains so much garbage, I put the complete drill trace into its own file with the relevant portion below (emphasis added):

;; Domain: xn--y9a3aq.
;; Signature ok but no chain to a trusted key or ds record
[S] xn--y9a3aq. 43200 IN DNSKEY 256 3 7 ;{id = 6707 (zsk), size = 1024b}
xn--y9a3aq. 43200 IN DNSKEY 257 3 7 ;{id = 58485 (ksk), size = 2048b}
xn--y9a3aq. 43200 IN DNSKEY 256 3 7 ;{id = 14567 (zsk), size = 1024b}
xn--y9a3aq. 43200 IN DNSKEY 257 3 7 ;{id = 47385 (ksk), size = 2048b}
[S] Existence denied: xn--y9a3aq. A
;;[S] self sig OK; [B] bogus; [T] trusted

Logfile examples