.mg TLD DNSSEC Outage: 2019-07-04

Date: July 4, 2019

Overview

This page gives some details on the .mg (Madagascar) TLD DNSSEC outage on July 4, 2019. This is at least the 28th 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 4, 2019:

July 4, 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 = 59263 (ksk), size = 2048b}
mg. 3600 IN DNSKEY 257 3 5 ;{id = 64652 (ksk), size = 2048b}
mg. 3600 IN DNSKEY 256 3 5 ;{id = 36951 (zsk), size = 1024b}
[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 mx mg. @8.8.8.8

; <<>> DiG 9.10.3-P4-Debian <<>> +dnssec mx mg. @8.8.8.8
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 6147
;; 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 MX

;; Query time: 2 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Thu Jul 04 09:54:35 UTC 2019
;; MSG SIZE rcvd: 31

You have to disable DNSSEC to make DNS queries work:

$ dig +cd mx mg. @8.8.8.8

; <<>> DiG 9.10.3-P4-Debian <<>> +cd mx mg. @8.8.8.8
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 64066
;; flags: qr rd ra cd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

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

;; AUTHORITY SECTION:
mg. 1799 IN SOA ns.nic.mg. ramboa.nic.mg. 2019070238 600 3600 604800 3600

;; Query time: 2 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Thu Jul 04 09:54:35 UTC 2019
;; MSG SIZE rcvd: 81

Logfile examples

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