Which tool should a network administrator use to read and write data over TCP and UDP?

Netcat is the most suitable tool for reading and writing data over both TCP and UDP protocols. It is a versatile networking utility that can establish connections, listen on specified ports, and transfer data in both directions. This functionality allows network administrators to create simple data transfer applications or communicate between devices over the network.

Additionally, in scenarios where testing or troubleshooting network services is necessary, Netcat can be used to send raw data, making it an indispensable tool for network diagnostics. The ability to specify protocol types (TCP or UDP) adds to its flexibility, allowing for a range of applications from simple data transfer to more complex network interactions.

While Tcpdump is a powerful packet capture tool suitable for monitoring traffic, it does not facilitate data writing over the network. It primarily focuses on packet analysis and capture, rather than data transmission. ssdeep is a tool geared towards computing and comparing file hashes for detecting similar files, while Vmstat is used for monitoring system performance metrics related to memory, processes, and CPU utilization—neither of which addresses the requirement for reading and writing network data.