Suggestions for a Comprehensive Network Monitoring Solution
Rubbernet
You can do this with Rubbernet. Install the daemon on all the Macs you want to monitor, then remotely monitor the apps (and the servers) that are using bandwidth.

Note that this screenshot is from an older version of the software and doesn't show the reverse IP lookup — it is possible to show the domain rather than the IP.


Real-time network dashboard
Rubbernet provides real-time monitoring so you can keep an eye on the exact state of your live network connections.

Remote monitoring
Monitor all computers on your network from one Rubbernet instance on your Mac. No need to get up and open Rubbernet on a remote Mac to see its network statistics.

Multi-user support
Have multiple user accounts on your Macs? Rubbernet automatically assigns every incoming and outgoing connections to the users they belong to.

App bandwidth usage
Rubbernet provide a breakdown of per-app network usage, so you can quickly detect apps that phone home, connect to certain servers without your knowledge, or blame the app that's slowing down your network.

Live graphs
Real-time charting displays download and upload transfer rates for all active apps on all monitored Macs

One-click enable/disable
Unlike other network monitoring tools, there is no complicated setup. It takes just a second to install or uninstall the necessary tools for Rubbernet to work. After that, they sit quietly in the background and provide the app with live data with minimal resource consumption.