Comment 1 for bug 1009658

OK, so the reason to do the nmap scan is to determine pingable ip addresses. Since this bug report is a testimony that this technique does not scale, we could potentially switch to other techniques; they won't be as thorough as brute-forcing every single IP in the range, but they can potentially yield reasonable results.

Sciri showed us a Fluke network diagnostics tool and what it does essentially is ping either the gateway or the DHCP server. Another possible technique is to send a broadcast ping to populate the ARP table and then take an IP from that. The internet_test script already contains code to do this, so it could potentially be reused.

A "best of both worlds" approach for network_bandwidth_test would be trying to use the above mentioned techniques, and fall back to nmap if no other usable IPs are found.

Also, tweaking nmap so it's faster (I see from the manpage that even with -sP it sends two or three probes per IP), or even using the "timeout" command to limit the time it takes to find hosts could make it more usable.

I'll set this as triaged so we can start working on it.