Skip to content

Instantly share code, notes, and snippets.

@bortzmeyer

bortzmeyer/postbank.md

Created November 14, 2019 09:59
Show Gist options
  • Star 0 You must be signed in to star a gist
  • Fork 0 You must be signed in to fork a gist
  • Save bortzmeyer/0e9d51b6f8bb2f4efe6663a89e47b1ac to your computer and use it in GitHub Desktop.
Save bortzmeyer/0e9d51b6f8bb2f4efe6663a89e47b1ac to your computer and use it in GitHub Desktop.
Download ZIP
Postbank / Google Public DNS problem, as seen by RIPE Atlas probes
Raw
postbank.md

Regular resolver (may be Google Public DNS):

% blaeu-resolve -r 100 --dnssec --displayvalidation --type A postbank.de
[160.83.8.182] : 38 occurrences 
[ (Authentic Data flag)  160.83.8.182] : 53 occurrences 
[ERROR: SERVFAIL] : 6 occurrences 
[ (Authentic Data flag) ] : 1 occurrences 
Test #23221499 done at 2019-11-14T09:53:54Z

Explicit use of Google Public DNS (not all instances have the problem):

% blaeu-resolve -r 100 --dnssec --displayvalidation --nameserver 8.8.8.8 --type A postbank.de
Nameserver 8.8.8.8
[ERROR: SERVFAIL] : 64 occurrences 
[ (Authentic Data flag)  160.83.8.182] : 30 occurrences 
[TIMEOUT] : 3 occurrences 
[160.83.8.182] : 1 occurrences 
Test #23221503 done at 2019-11-14T09:55:05Z

All three nameservers of postbank.de are in the same AS (206545), it could be a routing issue.

% check-soa postbank.de
ns1.postbank.de.
	185.157.33.19: OK: 2019111402
ns2.postbank.de.
	185.157.35.1: OK: 2019111402
ns3.postbank.de.
	185.157.35.19: OK: 2019111402
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment