.ar (Argentina) DNSSEC Outage: 2018-02-18

Updated: March 3, 2018

Overview

This page gives some details on the .ar (Argentina) DNSSEC outage on February 18, 2018. Although .ar itself was unaffected, its subdomains like com.ar, org.ar, etc. all expired and failed, effectively producing a total .ar DNSSEC outage. It lasted roughly 3 hours.

Timeline / DNSViz

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 fail:

$ dig +dnssec ns com.ar. @8.8.8.8

; <<>> DiG 9.4.2-P2 <<>> +dnssec ns com.ar. @8.8.8.8
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 29991
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

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

;; Query time: 37 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Sun Feb 18 18:51:51 2018
;; MSG SIZE rcvd: 35

You have to disable DNSSEC to make DNS queries work:

$ dig +cd ns com.ar. @8.8.8.8

; <<>> DiG 9.4.2-P2 <<>> +cd ns com.ar. @8.8.8.8
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 46570
;; flags: qr rd ra cd; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;com.ar. IN NS

;; ANSWER SECTION:
com.ar. 3599 IN NS b.dns.ar.
com.ar. 3599 IN NS e.dns.ar.
com.ar. 3599 IN NS ns2.switch.ch.
com.ar. 3599 IN NS c.dns.ar.
com.ar. 3599 IN NS a.dns.ar.

;; Query time: 24 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Sun Feb 18 18:51:51 2018
;; MSG SIZE rcvd: 119

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: ar.
[T] ar. 86400 IN DNSKEY 257 3 8 ;{id = 19606 (ksk), size = 4096b}
ar. 86400 IN DNSKEY 256 3 8 ;{id = 44889 (zsk), size = 2048b}
ar. 86400 IN DNSKEY 256 3 8 ;{id = 50229 (zsk), size = 2048b}
[B] Error verifying denial of existence for com.ar. DS: DNSSEC signature has expired
;; No ds record for delegation
;; Domain: com.ar.
;; No DNSKEY record found for com.ar.
[U] No data found for: com.ar. type A
;;[S] self sig OK; [B] bogus; [T] trusted

Logfile examples