Which command is useful for displaying network connections that are using the most bandwidth?

The command that is most useful for displaying network connections that are using the most bandwidth is iftop. This utility provides a real-time view of bandwidth usage on a network interface, showing which hosts are using the most bandwidth at any given moment. It displays the connections along with the data transfer rates in an intuitive format, which helps users easily identify bandwidth-hogging connections.

While netstat is a versatile command for examining network connections, routing tables, and interface statistics, it does not specifically focus on active bandwidth usage per connection. Similarly, ntop is a traffic monitoring tool that provides extensive reporting and can give insights into bandwidth usage but is generally considered more complex and suited for long-term analytics rather than immediate connection-level data. tcpdump, on the other hand, is a packet capture tool that allows users to analyze traffic at a low level; it captures packets but does not inherently display bandwidth usage in a summarized or user-friendly fashion.

Therefore, iftop stands out as the most appropriate command for the task of showing which network connections are consuming the most bandwidth, providing the most relevant insights into real-time usage.