Google Cloud DNS - internal lan - Unable to resolve nameservers for this domain

[DE-mbecker]

Hi,

I'm trying to install cloudron in a lan environment where it is not reachable from the public internet. Therefore I delegated the subdomain cloudron.mb-it.com from my dns provider to google cloud dns. Here are the details I entered into the setup screen (advanced mode):

• Domain: cloudron.mb-it.com
• DNS Provider: Google Cloud DNS
• Service Account Key: Uploaded the json for the service account
• DNS Zone name: cloudron
• Certificate Provider: Let's encrypt Prod - Wildcard / Self Signed (tried both)
• IPv4 Configuration: static internal IP of my server
• IPv6 Configuration: disabled

When I log in to server via ssh and enter the following command, I get the right answer

# host -t NS cloudron.mb-it.com
cloudron.mb-it.com name server ns-cloud-e1.googledomains.com.
cloudron.mb-it.com name server ns-cloud-e3.googledomains.com.
cloudron.mb-it.com name server ns-cloud-e4.googledomains.com.
cloudron.mb-it.com name server ns-cloud-e2.googledomains.com.

Still I got the error message "Unable to resolve nameservers for this domain". Can someone give me a hint how to solve this?

Thanks in advance and best regards
Marc