.mg TLD DNSSEC Outage: 2019-07-26

Date: July 26, 2019

Overview

This page gives some details on the .mg (Madagascar) TLD DNSSEC outage on July 26, 2019. This is at least the 30th DNSSEC outage for Madagascar.

Timeline / DNSViz

(At the time of this writing, DNSViz historical archives have been down for months. DNSSEC makes its users think downtime doesn't matter.)

DNSSEC Debugger

Verisign's DNSSEC Debugger doesn't archive results, so here's a screenshot of my web browser's output from July 26, 2019:

July 26, 2019 .mg TLD DNSSEC outage

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: mg.
[B] mg. 3600 IN DNSKEY 257 3 5 ;{id = 64652 (ksk), size = 2048b}
mg. 3600 IN DNSKEY 256 3 5 ;{id = 36951 (zsk), size = 1024b}
mg. 3600 IN DNSKEY 257 3 5 ;{id = 59263 (ksk), size = 2048b}
[B] Error verifying denial of existence for mg. type A: No keys with the keytag and algorithm from the RRSIG found
;;[S] self sig OK; [B] bogus; [T] trusted

Google 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.

$ dig +dnssec ns mg. @8.8.8.8

; <<>> DiG 9.4.2-P2 <<>> +dnssec ns mg. @8.8.8.8
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 38899
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

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

;; Query time: 398 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Fri Jul 26 17:43:58 2019
;; MSG SIZE rcvd: 31

You have to disable DNSSEC to make DNS queries work:

$ dig +cd ns mg. @8.8.8.8

; <<>> DiG 9.4.2-P2 <<>> +cd ns mg. @8.8.8.8
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 45055
;; flags: qr rd ra cd; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;mg. IN NS

;; ANSWER SECTION:
mg. 7199 IN NS pch.nic.mg.
mg. 7199 IN NS ns.dts.mg.
mg. 7199 IN NS ns.nic.mg.
mg. 7199 IN NS censvrns0001.ird.fr.
mg. 7199 IN NS ns-mg.malagasy.com.

;; Query time: 149 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Fri Jul 26 17:43:58 2019
;; MSG SIZE rcvd: 145

Logfile examples

These Unbound log entries come from different Unbound instances, each on different servers in different geographical regions.