Dns sometimes fails using Google DNS / automatic dnssec

MailPlus| David Hofstee david at mailplus.nl
Thu Nov 15 14:12:23 UTC 2012


Hi,

We've been seeing automatic RRSIG records on Google DNS lately, the 8.8.8.8 en 8.8.4.4. They are not always provided. They cause problems for some of our customers in a weird way I cannot explain. For them these records do not resolve but I cannot reproduce it.

So when I run dig command

dig @8.8.8.8 m1.mailplus.nl

it often provides the RRSIG record (but e.g. the TXT record will not be signed). I've heard that DNS may fall back to TCP and/or may be filtered by firewalls if UDP is over 512 bytes. However, the request is not that long, about 200 bytes if I interpret the answer correctly.

Can someone come up with a good explanation why a tiny percentage of our customers cannot resolve (some of) our domains?

Btw, our nameservers (transip.nl) only provide DNSSEC records if explicitly asked. What is standard here?


Thanks,

David Hofstee


More information about the NANOG mailing list