portsentry command not found

Introduction

When you run more command in linux terminal / console, you get the following error message

portsentry: command not found

or when using sudo you get the following error message

sudo: portsentry: command not found

Solutions to portsentry: command not found

How To Fix portsentry: command not found in Ubuntu / Debian / Kali Linux / Raspbian

In Ubuntu portsentry is provided by portsentry package.

portsentry is:

PortSentry has the ability to detect portscans(including stealth scans) on the network interfaces of your machine. Upon alarm it can block the attacker via hosts.deny, dropped route or firewall rule. It is part of the Abacus program suite.

Note: If you have no idea what a port/stealth scan is, It’s recommended to have a look at http://sf.net/projects/sentrytools/ before installing this package. Otherwise you might easily block hosts you’d better not (e.g. your NFS-server, name-server, etc.).

To fix this problem, we can install more using the command below.

sudo apt-get -y install portsentry

This command might take some time to finish depending on your machine internet connection.

You can also use apt command to install portsentry.

sudo apt -y install portsentry

Or if you have aptitude installed you can use the following command.

sudo aptitude install portsentry

Summary

In this tutorial we learn how to fix portsentry command not found error in Ubuntu / Debian / Kali Linux or Raspbian distribution.