.zm (Zambia) DNSSEC Outage: 2018-04-15

Date: April 15, 2018

Overview

This page gives some details on the .zm TLD DNSSEC outage on April 15, 2018.

DNSViz / Timeline

DNSSEC Debugger

Unlike DNSViz, Verisign's DNSSEC Debugger doesn't archive results, so here's a screenshot of my web browser's output from April 15, 2018:

April 15, 2018 .zm (Zambia) 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 DNS SEC. With DNSSEC, DNS queries result in SERVFAIL:

$ dig +dnssec ns zm. @8.8.8.8

; <<>> DiG 9.4.2-P2 <<>> +dnssec ns zm. @8.8.8.8
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 34062
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

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

;; Query time: 39 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Sun Apr 15 04:21:53 2018
;; MSG SIZE rcvd: 31


You have to disable DNSSEC to make DNS queries work:

$ dig +cd ns zm. @8.8.8.8

; <<>> DiG 9.4.2-P2 <<>> +cd ns zm. @8.8.8.8
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 51884
;; flags: qr rd ra cd; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;zm. IN NS

;; ANSWER SECTION:
zm. 21599 IN NS pch.nic.zm.
zm. 21599 IN NS ns1.zamnet.zm.
zm. 21599 IN NS ns-zm.afrinic.net.
zm. 21599 IN NS ns2.zamnet.zm.

;; Query time: 16 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Sun Apr 15 04:21:53 2018
;; MSG SIZE rcvd: 116

Zonemaster

drill trace

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

;; Domain: zm.
[B] zm. 3600 IN DNSKEY 256 3 8 ;{id = 1059 (zsk), size = 1024b}
zm. 3600 IN DNSKEY 257 3 8 ;{id = 32227 (ksk), size = 2048b}
[B] Error verifying denial of existence for zm. type A: No keys with the keytag and algorithm from the RRSIG found
;;[S] self sig OK; [B] bogus; [T] trusted

Logfile examples