RHEL Linux Red Hat System Administration 2025 – 400 Free Practice Questions to Pass the Exam

To display all active network connections, the command `netstat -tuln` is indeed the appropriate choice. This command is part of the netstat suite of network utilities that provides information about network connections, routing tables, interface statistics, masquerade connections, and multicast memberships.

When using `netstat -tuln`:

- The `-t` option indicates that you want to display TCP connections.

- The `-u` option shows UDP connections.

- The `-l` option limits the output to only show listening sockets, which is particularly useful for identifying services that are awaiting incoming connections.

- The `-n` option displays the addresses and port numbers in numeric format rather than resolving them to hostnames and service names, making the output faster and sometimes clearer.

Combining these flags gives a comprehensive view of both TCP and UDP sockets that are currently active, including those that are listening for new connections.

In contrast, while `netstat -an` would also provide a list of all active connections and listening ports without resolving names (the `-n` flag), it does not focus solely on the distinctions between TCP and UDP and might include more output than necessary for someone specifically interested in active connections and listening services.