The best way to discover the topology of a network is to run a topology discovery using NMAP.
- # nmap -sP 10.1.2.0/24. Now known as #nmap -sn 10.1.2.0/24. This option tells Nmap not to do a port scan after host discovery, and only print out the available hosts that responded to the host discovery probes. This is often known as a “ping scan”.
- # nmap -sL 10.1.2.0/24 – This scan uses DNS to flesh out a network and doesn’t send any packets to the system.