Score:0

DNS issue with previously working site - ping shows "Name or service not known"

ph flag

A website I am responsible for, running in the cloud (at Hetzner), suddenly became unavailable yesterday because of a DNS issue. The server itself is up and running fine and can be accessed by IP address. Yesterday a ping resulted in "Ping request could not find host [xxx]. Please check the name and try again." Today it has moved on to "ping: [xxx]: Name or service not known". It's not a local issue with my DNS - https://downforeveryoneorjustme.com/ shows it's down and I've tried a ping from various locations. I'm at a loss to understand where this problem might be. It's a valid, up to date domain, but domain name resolution has suddenly stopped working for it.

Carlo avatar
cn flag
Can you ping other public ip from server? Internet is working?
John Moore avatar
ph flag
Well, I can ssh into that server from elsewhere, so yes. And I can ping other sites from there.
Carlo avatar
cn flag
And you have A record in dns zone pointing to server public ip ?
John Moore avatar
ph flag
Yes. It is a service which has been working successfully for the last year. Nothing has been changed, but some DNS issue has suddenly appeared.
Carlo avatar
cn flag
I have no experience with Hetzner VPS but it looks to me as network issue. If you have public ip assigned to wan facing interface, A record in dns zone, and a properly configured web server it should work. You can ping from server but server is not accessible from wan. Is there any security settings applied? Firewall in front of the vm or iptables? Can you please check that server has the same public ip as specified in dns A record?
John Moore avatar
ph flag
It turns out that someone has accessed the domain name control panel and deleted the subdomain, among other changes. Not sure who. Didn't even cross my mind that this might have happened. Until today I had no access to the domain name control panel to check it out.
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