.mg TLD DNSSEC Outage: 2019-07-15
Date: July 15, 2019
Overview
This page gives some details on the .mg (Madagascar) TLD DNSSEC outage on July 15, 2019. This is at least the 29th DNSSEC outage for Madagascar.
Timeline / DNSViz
(At the time of this writing, DNSViz historical archives have been down for months. DNSSEC makes its users think downtime doesn't matter.)
- 2019-07-15 13:06:37 UTC — first personally observed .mg DNSSEC failure, "signature before inception date"
- 2019-07-15 13:35:48 UTC — last personally observed .mg DNSSEC failure, "signature before inception date"
DNSSEC Debugger
Verisign's DNSSEC Debugger doesn't archive results, so here's a screenshot of my web browser's output from July 15, 2019:
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: mg.
[B] mg. 3600 IN DNSKEY 256 3 5 ;{id = 36951 (zsk), size = 1024b}
mg. 3600 IN DNSKEY 257 3 5 ;{id = 64652 (ksk), size = 2048b}
mg. 3600 IN DNSKEY 257 3 5 ;{id = 59263 (ksk), size = 2048b}
[B] Error verifying denial of existence for mg. type A: No keys with the keytag and algorithm from the RRSIG found
;;[S] self sig OK; [B] bogus; [T] trusted
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 a mg. @8.8.8.8
; <<>> DiG 9.4.2-P2 <<>> +dnssec a mg. @8.8.8.8
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 63052
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags: do; udp: 512
;; QUESTION SECTION:
;mg. IN A
;; Query time: 27 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Mon Jul 15 13:06:40 2019
;; MSG SIZE rcvd: 31
You have to disable DNSSEC to make DNS queries work:
$ dig +cd a mg. @8.8.8.8
; <<>> DiG 9.4.2-P2 <<>> +cd a mg. @8.8.8.8
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 64712
;; flags: qr rd ra cd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0
;; QUESTION SECTION:
;mg. IN A
;; AUTHORITY SECTION:
mg. 1799 IN SOA ns.nic.mg. ramboa.nic.mg. 2019071504 600 3600 604800 3600
;; Query time: 28 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Mon Jul 15 13:06:40 2019
;; MSG SIZE rcvd: 70
Logfile examples
These Unbound log entries come from different Unbound instances, each on different servers in different geographical regions.
- [1563195997] unbound[19622:0] info: validation failure <mg. NS IN>: signature before inception date from 91.203.32.147 for key mg. while building chain of trust
- [1563196732] unbound[16058:0] info: validation failure <dnssec.co.mg. NS IN>: key for validation mg. is marked as invalid because of a previous validation failure <mg. NS IN>: signature before inception date from 87.98.132.231 for key mg. while building chain of trust
- [1563197748] unbound[19622:0] info: validation failure <mg. NS IN>: signature before inception date from 204.61.216.121 for key mg. while building chain of trust