gsu.edu DNSSEC Outage: 2019-06-04

Date: June 4, 2019

Overview

This page gives some details on the gsu.edu (Georgia State University) DNSSEC outage on June 4, 2019.

Timeline / DNSViz

At the time of this writing, DNSViz historical archives have been failing for a couple months, and may be permanently down. DNSSEC makes its users completely give up.

I've included screenshots of DNSViz output since DNSSEC people don't seem to care if things work or not.

June 4, 2019 gsu.edu DNSSEC outage

DNSSEC Debugger

Verisign's DNSSEC Debugger doesn't archive results, so here's a screenshot of my web browser's output from June 4, 2019.

June 4, 2019 gsu.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 a gsu.edu. @8.8.8.8

; <<>> DiG 9.4.2-P2 <<>> +dnssec a gsu.edu. @8.8.8.8
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 42484
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

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

;; Query time: 69 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Tue Jun 4 12:02:11 2019
;; MSG SIZE rcvd: 36

You have to disable DNSSEC to make DNS queries work:

$ dig +cd a gsu.edu. @8.8.8.8

; <<>> DiG 9.4.2-P2 <<>> +cd a gsu.edu. @8.8.8.8
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 21782
;; flags: qr rd ra cd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;gsu.edu. IN A

;; ANSWER SECTION:
gsu.edu. 3599 IN A 166.78.46.98

;; Query time: 66 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Tue Jun 4 12:02:11 2019
;; MSG SIZE rcvd: 41

dns.google.com

dns.google.com is related to but separate from Google Public DNS. During this DNSSEC outage, dns.google.com showed the following for gsu.edu:

May 20, 2019 dns.google.com output for gsu.edu

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: gsu.edu.
[T] gsu.edu. 3600 IN DNSKEY 257 3 5 ;{id = 30514 (ksk), size = 2048b}
gsu.edu. 3600 IN DNSKEY 256 3 5 ;{id = 59262 (zsk), size = 1024b}
gsu.edu. 3600 IN DNSKEY 256 3 5 ;{id = 33046 (zsk), size = 1024b}
gsu.edu. 3600 IN DNSKEY 257 3 5 ;{id = 3547 (ksk), size = 2048b}
[B] gsu.edu. 3600 IN A 166.78.46.98
;; Error: DNSSEC signature has expired
;;[S] self sig OK; [B] bogus; [T] trusted

Logfile examples