nau.edu DNSSEC Outage:
2018-01-20 - 2018-01-21

Updated: January 22, 2018

Overview

This page gives some details on the nau.edu (Northern Arizona University) DNSSEC outage from January 20 to January 21, 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 January 20, 2018.

January 20, 2018 nau.edu DNSSEC outage

Zonemaster

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 www.nau.edu. @8.8.8.8

; <<>> DiG 9.4.2-P2 <<>> +dnssec www.nau.edu. @8.8.8.8
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 24915
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags: do; udp: 512
;; QUESTION SECTION:
;www.nau.edu. IN A

;; Query time: 87 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Sat Jan 20 17:33:31 2018
;; MSG SIZE rcvd: 40

You have to disable DNSSEC to make DNS queries work:

$ dig +cd www.nau.edu. @8.8.8.8

; <<>> DiG 9.4.2-P2 <<>> +cd www.nau.edu. @8.8.8.8
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 3257
;; flags: qr rd ra cd; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;www.nau.edu. IN A

;; ANSWER SECTION:
www.nau.edu. 299 IN CNAME nau.edu.
nau.edu. 299 IN A 198.90.22.157

;; Query time: 18 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Sat Jan 20 17:33:31 2018
;; MSG SIZE rcvd: 59

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: nau.edu.
;; Signature ok but no chain to a trusted key or ds record
[S] nau.edu. 86400 IN DNSKEY 256 3 5 ;{id = 258 (zsk), size = 1024b}
nau.edu. 86400 IN DNSKEY 257 3 5 ;{id = 45277 (ksk), size = 2048b}
[S] nau.edu. 300 IN A 198.90.22.157
;;[S] self sig OK; [B] bogus; [T] trusted

Logfile examples