deny / allow hosts

@ http://www.linuxquestions.org/questions/linux-newbie-8/how-to-configure-ssh-to-allow-or-deny-specify-host-ip-address-610246/

/etc/hosts.deny is checked before /etc/hosts.allow, so you can go

* hosts.deny
ALL : ALL

first, we block everything from everyone,

* hosts.allow
ALL : localhost
sshd: 192.168.0.22
proftpd: 192.168.0.22

which means only 192.168.0.22 on your local network
can access ssh or the proftp server on that machine.