Nmap 3.70 released -> http://www.insecure.org/


this simple command allows to know which local hosts are up::


   nmap -sP <masked IP network>   (ex: nmap -sP 192.168.1.0/24 )


This friendly scanning can be added to the crontab, allowing a daily report of the open ports::

  nmap -sT -P0 -sV <host> 2>&1 | mail -b <your mail> \ 
   -s "[nmap] `date -I` scan report" <host_owner_mail>

For IPv6::
  
  nmap -sT -6 -P0 -sV <host|ipv6>