.ss TLD DNSSEC Outage: 2020-07-02

Date: July 2, 2020

Overview

This page gives some details on the .ss (South Sudan) TLD DNSSEC outage on July 2, 2020.

Timeline / DNSViz

Since DNSViz loses data regularly, there is an archive at archive.is. There is also a copy courtesy of archive.org.

DNSSEC Debugger

Here's a screenshot of my web browser's output from July 2, 2020.

July 2, 2020 .ss (South Sudan) TLD DNSSEC outage

There is a copy of DNSSEC Debugger output saved by archive.is.

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 ns ss. @8.8.8.8

; <<>> dig 9.10.8-P1 <<>> +dnssec ns ss. @8.8.8.8
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 18994
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

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

;; Query time: 28 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Thu Jul 02 18:03:42 UTC 2020
;; MSG SIZE rcvd: 31

You have to disable DNSSEC to make DNS queries work:

$ dig +cd ns ss. @8.8.8.8

; <<>> dig 9.10.8-P1 <<>> +cd ns ss. @8.8.8.8
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 37338
;; flags: qr rd ra cd; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 1

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

;; ANSWER SECTION:
ss. 21599 IN NS b.ns.tznic.or.tz.
ss. 21599 IN NS pch.nic.ss.
ss. 21599 IN NS root.nic.ss.
ss. 21599 IN NS ns-ss.afrinic.net.
ss. 21599 IN NS ssnic.anycastdns.cz.

;; Query time: 177 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Thu Jul 02 18:03:42 UTC 2020
;; MSG SIZE rcvd: 166

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):

ss. 86400 IN DS 43817 8 2 f85d36a2e056ff8cbb8dc79c748e4ec1e862c4f739891f9595669aa3384a252d
;; Domain: ss.
;; Signature ok but no chain to a trusted key or ds record
[S] ss. 3600 IN DNSKEY 256 3 8 ;{id = 7908 (zsk), size = 1024b}
ss. 3600 IN DNSKEY 257 3 8 ;{id = 35431 (ksk), size = 2048b}
[B] Error verifying denial of existence for ss. type A: No keys with the keytag and algorithm from the RRSIG found
;;[S] self sig OK; [B] bogus; [T] trusted

Logfile examples

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