.moscow TLD DNSSEC Outage: 2018-11-06

Date: November 6, 2018

Overview

This page gives some details on the .moscow DNSSEC outage on November 6, 2018.

Timeline / DNSViz

DNSSEC Debugger

Unlike DNSViz, Verisign's DNSSEC Debugger doesn't archive results, so here's a screenshot of my web browser's output from November 6, 2018:

November 6, 2018 .moscow DNSSEC outage

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 moscow. @8.8.8.8

; <<>> DiG 9.4.2-P2 <<>> +dnssec ns moscow. @8.8.8.8
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 44726
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

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

;; Query time: 197 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Tue Nov 6 15:08:08 2018
;; MSG SIZE rcvd: 35

You have to disable DNSSEC to make DNS queries work:

$ dig +cd ns moscow. @8.8.8.8

; <<>> DiG 9.4.2-P2 <<>> +cd ns moscow. @8.8.8.8
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 61016
;; flags: qr rd ra cd; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;moscow. IN NS

;; ANSWER SECTION:
moscow. 21278 IN NS c.dns.flexireg.org.
moscow. 21278 IN NS a.dns.flexireg.ru.
moscow. 21278 IN NS b.dns.flexireg.net.
moscow. 21278 IN NS d.dns.flexireg.domains.

;; Query time: 8 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Tue Nov 6 15:08:08 2018
;; MSG SIZE rcvd: 155

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: moscow.
;; Signature ok but no chain to a trusted key or ds record
[S] moscow. 345600 IN DNSKEY 257 3 8 ;{id = 49150 (ksk), size = 2048b}
moscow. 345600 IN DNSKEY 256 3 8 ;{id = 4560 (zsk), size = 1024b}
[S] Existence denied: moscow. A
;;[S] self sig OK; [B] bogus; [T] trusted

Logfile examples