Which command would you use to view listening ports and current TCP connections on Linux?

• A. arp -a
• B. ss -ntlp
• C. netstat -ano Windows
• D. netstat -tunp on Linux

Answer: (D)

To inspect sockets and their states on Linux, you want a command that lists listening ports and active TCP connections, along with the owning process. Using netstat with options -t, -u, -n, and -p provides that view: -t shows TCP, -u includes UDP as well (not required but harmless), -n outputs numeric addresses to avoid DNS lookups, and -p shows the process ID and program name owning each socket. The resulting output includes entries in the LISTEN state for ports waiting for connections as well as ESTABLISHED entries for current TCP connections, all labeled with the associated program. Other options either target unrelated data, show only listening sockets, or apply to a different OS, so this command best fits the request.