Your browser does not seem to support JavaScript. As a result, your viewing experience will be diminished, and you have been placed in read-only mode.
Please download a browser that supports JavaScript, or enable it if it's disabled (i.e. NoScript).
The online/offline status is just whether those IPs appear in the system's ARP cache. You can add static mappings if you want to see that online/offline display. But you can't run your own DHCP server in AWS.