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Silvan Michael Gebhardt

Unternehmer, Informatiker, Network Operator

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Broken DNS replication

A few people were complaining that they can’t seem to open up my blog and see part of the openfactory website. a few facts for these people:

  • You’re obviously using ipv6. Even if you did not know that you were using it
  • My DNS did mix up. At least one of the two. That’s why it worked for me apparently
  • The issue is due to a wrong IP and then the IP did not match
  • I’m running ipv6 and ipv4 on this blog

Issue

Well apparently my secondary DNS did not like to synchronize anymore. I’m using the same setup as our hosting partners (novatrend) is using, but on dedicated servers. So we run cpanel with a lot of stuff (e.g cloudlinux for isolation)

Apparently the ANTI-Bruteforce Service (cphulkd) did decide to blacklist my DNS masters IP adress - whitelisting did fix it. Resetting all keys and everything else? Hopeless. Whitelist the Main Webserver on the secondary DNS if you want it to run reliable.

I guess this might help someone else, I did rant for at least an hour till I managed to fix this, since I got blacklisted almost instantly aswell I did first guess someone changed the password without telling me. GRR.