Perform a stealthy very slow scan ('-T0') trying to avoid detection by IDS/IPS and use decoy ('-D') source IP addresses
nmap -T0 -D {{decoy1_ipaddress,decoy2_ipaddress,...,decoyN_ipaddress}} {{address_or_addresses}}
nmap -T0 -D {{decoy1_ipaddress,decoy2_ipaddress,...,decoyN_ipaddress}} {{address_or_addresses}}