About portsentry you could googling. I will share my knowladge about portsentry installation.
1. Please update your ubuntu server.
Login as root with sudo su and using apt-get update -y
2. Installing portsentry.
#apt-get install portsentry
3. Edit portsentry configuration file
# gedit /etc/portsentry/
So like this
next, looking for row
#KILL_ROUTE=”/sbin/route add -host $TARGET$ gw 333.444.555.666″
and remove # and change 333.444.555.666 with reject
so like this
KILL_ROUTE=”/sbin/route add -host $TARGET$ reject”
4. restart your portsentry
# /etc/init.d/portsentry start
For examination you can use nmap application from client to your sever was installed portsentry. Look at your log with #tail -f /var/log/syslog
pleasea don’t forget look at your /etc/. This file is place ip address was blocked because scanner activity.
Look at /var/lib/portsentry/portsentry.history . thsi file is was note a history ip address was was blocked because scanner activity.