useful nmap scans

enumerate and find as much information of the top 1000 ports (recommended first scan):

$ nmap --top-ports 1000 -T4 -sC

network sweeping:

$ nmap -sn

scan for the top 20 TCP ports and save output in a file:

$ nmap -sT -A --top-ports=20 -oG top-port-sweep.txt

banner grabbing, service ennumeration:

$ nmap -sV -sT

OS identifying:

$ nmap -O

attempt to connect to the SMB service:

$ nmap --script smb-os-discovery.nse

DNS zone transfer NSE script

$ nmap --script=dns-zone-transfer -p 53 
Written on August 9, 2017