Which tool would an administrator use to test connectivity of a server in the cloud?

Using the ping tool is an effective way to test the connectivity of a server in the cloud. This command sends ICMP echo request packets to a specified IP address or hostname and waits for a response. A successful reply indicates that the server is reachable over the network, while a lack of response can denote issues such as network failures, firewall settings, or the server being down.

Ping is widely used due to its simplicity and the immediate feedback it provides about a server's availability and round-trip time for data packets. In cloud environments, where network configurations can change frequently, using ping helps administrators quickly verify whether the resources they are managing are accessible.

FTP (File Transfer Protocol) is mainly used for transferring files and is not suited for testing connectivity directly. nslookup is used for querying DNS servers to obtain domain name or IP address mappings, which does not indicate the actual connectivity to a server after resolution. Netstat is a network utility that displays active connections and port statistics on a local machine, but it does not test the connectivity of remote servers.

Thus, the ping tool stands out for its specific purpose of validating connectivity to a server in cloud computing environments.