With the iptables configuration files I've got...
All is closed, and only few thing are open to access the server, and to restrict at the maximum ressources access.. and protect the virtual private lan from the public lan.
Even icmp is restricted....
I will make
CIDR object for subnets.
host groups for bunches of computers, printer and server.
services, to specify with service I will open/close ( ICMP, windows shares, datavase ports...)
But there's iptables rules, anti sniffer and kernel protection, I don't have the minor idea how to implement....
Is Nethserver has sort of rules by default?
Edit: is a client station can be in two hosts groups at the same time?
Unfortunatly, I can create the firewall objects because It's not possible to create empty object 
