Normally, if you did any setup before pointing the domain to the host, or if you connect via ssh, then you at least have seen the ip and probably have it record

Normally, if you did any setup before pointing the domain to the host, or if you connect via ssh, then you at least have seen the ip and probably have it recorded in files like ~/.ssh/known_hosts. But generally, the better your setup is documented, the better you can detect or diagnose when something goes awry.