LibreNMS: What is it and how does it work?

LibreNMS gUIDE

This article covers the LibreNMS network monitoring tool, from installation and configuration to features and usage. Introduction to LibreNMS LibreNMS is a powerful open-source network monitoring solution that can be used to monitor devices and services on your network. It offers a wide range of features, including support for a variety of protocols, performance monitoring, alerts, and more. LibreNMS is easy to install and configure, and it can be used on a variety of platforms. In this guide, we will cover the basics of LibreNMS, … Read more

How to Install and Use Netstat on Linux (CentOS/RHEL, Debian/Ubuntu, OpenSuse & Arch Linux)

How to Install and Use Netstat on Linux

This article provides a tutorial on how to install and use Netstat, a command-line network tool, on Linux. Netstat is a command-line utility that can be used to view network connections, routing tables, and a variety of other network-related information on Linux systems. While Netstat is typically used to troubleshoot network issues, it can also be used for tasks such as monitoring server traffic or checking which ports are open on a system. Why Use Netstat? Netstat is a network monitoring tool that can be … Read more

How to Install Webmin on Ubuntu 20.04

How to Install Webmin on Ubuntu

Webmin is a system configuration tool that can be run on Linux. This step-by-step tutorial explains how to install Webmin on Ubuntu 20.04. Webmin makes it easy for newbies (and veterans) to monitor and manage their Linux system and the services running on it in a graphical, browser-based interface that can be accessed locally or remotely. It’s a great tool for people getting started to manage users, web server configurations, file servers, and more. Webmin includes a bunch of modules for common software like Apache … Read more

Top 5 Linux Monitoring Tools. Web Based.

Monitoring (featured logo)

Linux system monitoring is one of the most important tasks for every sysadmin: it is crucial to know everything about system including CPU load, network traffic statistics, memory consumption, logged in users, availability of disk free space or service. And it’s inevitable that something breaks or goes down from time to time so usually it’s just better to know it happened from Linux monitoring system’s alert rather than from angry user. Believe me, it is true. In this article I’ve listed top 5 web based … Read more

Fix socket timeouts in Nagios

Nagios (featured logo)

As any other monitoring system Nagios can produce false alarms. Usually it happens when Nagios fails to get the reply from the host being monitored during some pre-defined timeout. In order to mark service as down Nagios does three checks and if all of them are failed then the service is marked down and administrator will got an alert about its critical status. At the same time even if one of those checks fails Nagios will report administrator about it depending on configuration (e-mail, twitter, … Read more

Nfsen: Traffic Classification

Monitoring (featured logo)

Nfsen is open source sensor: it accepts netflow data from multiple netflow probes (servers, routers, vpn concentrators etc) and then visualizes it into human readable form. So using Nfsen you can see traffic statistics of every network device in your network in one place (actually Nfsen provides much more features).

By default Nfsen makes it possible to see only inbound and outbound traffic statistics but no protocol breakdown or any traffic classification. In the meantime it’s always useful to know what network applications are eating the bandwidth to understand if that fits baseline or not and take necessary actions. For example, if you’re monitoring Linux server which primary task is to host some website but in Nfsen you see that it generates 90% of SSH traffic and only 10% of web traffic then it would be reasonable idea to check if somebody is trying to brute force SSH password and stop that activity. In other words it’s better to have traffic statistics classified. In this article I’ll tell you how to enable traffic classification in Nfsen.

rrdgraph

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