How can I test connection to these domains?

Beyond just pinging the domains used by Cyber Crucible to make sure that your endpoint can reach all of the correct network address, the Cyber Crucible Agent installer includes a test argument that ensures a valid TLS/SSL connection can be made in both directions to all required servers.

Simply add --test-connection to the installer execution, making sure to still include group id(s) and OAuth tokens that are necessary to perform authentication. Seen above is a screenshot showing the only modification needed to the provided .bat script, and a successful output.