Posted by Zach C. on Jan 03
Yet another note, this one ARP-related: while true that most devices on
your local network will respond to ARP, it's important to note (as the
wording of "almost certain" implies) that it is possible to purposely
suppress ARP responses to all but a few hosts. I know for certain that the
Linux kernel has a module (and associated toolset) specifically for that
sort of thing called arptables, with usage very similar to iptables if…
Source: Re: Nmap