Zabbix Agent installation and Passive monitoring

At this point we are familiar with the Zabbix dataflow, how to create hosts and, add interfaces and items to a host. As a system administrator or anyone else working with Linux, Unix or Windows systems usually we jump right into installing the Zabbix agent and monitoring with it. Using our previous steps however, we have laid the groundwork for building a proper monitoring solution. We have prepared our systems before monitoring, which is the most important part to avoid Monitoring fatigue later on.

Note

Monitoring fatigue and Alert fatigue are two terms heard in monitoring and observability.

Alert fatigue happens in Zabbix when you configure too many (incorrect) triggers. When you flood your dashboards or even external media like Teams or Signal with too many alerts your users will not respond to them any longer.

Monitoring fatigue happens in Zabbix when you misconfigure things like dashboards, items, host groups, tags and other internal systems that keep things structured. The result is that you or your co-workers do not want to use your own system any longer as it does not deliver the right information easily enough.

Now, we are ready to start monitoring an actual system.

Agent basics

We have prepared an example setup in our Book LAB environment.

Zabbix Agent passive hosts

4.14 Zabbix Agent passive hosts

What we can see here is a setup you might see in any datacenter or office server cabinet. We have a Zabbix server monitoring one Windows server and one Linux server directly (or through a proxy). We call Zabbix a network monitoring solution as it communicates over the network. In Zabbix we have two methods of communication.

Passive Otherwise known as polling. We communicate from the Zabbix server (or proxy) towards the monitoring target. The monitoring target is listening on a port waiting for Zabbix to request data.
Active Otherwise known as trapping. We communicate from the monitoring target towards the Zabbix server (or proxy). The Zabbix server is listening on a port waiting for the monitoring target to send data.

As you can imagine there is quite a big difference between these two methods of communication. Often times it depends on the protocol which method is preferred. For example SNMP traps are always an active type of check.

The Zabbix agent however can communicate in either Active or Passive mode. It can even do those simultaneously. Simultaneous communication can be useful when you want to use Passive mode for all communication, but still want to execute some items that are Active only. Active items can do everything Passive items can do however.

Before we can configure either though, we will have to install our Zabbix agent first. When installing on Linux and Windows we have a choice between two different agents, Zabbix agent and Zabbix agent 2. Both of these Zabbix agents are still in active development and receive both major (LTS) and minor updates. The difference between them is in Programming language and features.

	Zabbix agent	Zabbix agent 2
Features	No focus to include new features	Supports everything agent 1 does + more
Programming language	C	GoLang
Extensions	C Loadable Modules	GoLang plugins
Platforms	All	Linux and Windows
Concurrency	In sequence	Concurrently
Storage on outage	No	Sqlite
Item timeouts	Agent wide	Per plugin

Agent installation on Linux

Installation on Linux can be done in one of three ways. Through direct install files like .rpm and .deb, by building from sources and through packages pulled from the repository. Installation through the packages is preferred as this means Zabbix agent will be updated when updating with commands like dnf update and apt upgrade. Keep in mind, Zabbix agent is a piece of software just like any other and as such news versions will contain security and bug fixes. Whatever installation method you choose, keep your Zabbix agent up-to-date.

We will be using the packages on both RedHat-based and Ubuntu to install Zabbix agent 2. To use the packages we will add the Zabbix repository first.

add zabbix repository

Redhat

rpm -Uvh https://repo.zabbix.com/zabbix/7.2/release/rocky/9/noarch/zabbix-release-latest-7.2.el9.noarch.rpm
dnf clean all

Ubuntu

sudo wget https://repo.zabbix.com/zabbix/7.2/release/ubuntu/pool/main/z/zabbix-release/zabbix-release_latest_7.2+ubuntu24.04_all.deb
sudo dpkg -i zabbix-release_latest_7.2+ubuntu24.04_all.deb
sudo apt update

After adding the repository, we should be able to install Zabbix agent 2.

install Zabbix agent 2 package

Redhat

dnf install zabbix-agent2

Ubuntu

sudo apt install zabbix-agent2

After installation make sure to start and enable the Zabbix agent.

start Zabbix agent 2

Redhat

systemctl start zabbix-agent2
systemctl enable zabbix-agent2

Your agent is now installed under the zabbix user and ready to be configured. On a Linux based system, by default we can find all of the Zabbix configuration files in /etc/zabbix/. Specifically we want to edit /etc/zabbix/zabbix_agent2.conf.

Agent installation on Windows

On Windows, we have two options to install our Zabbix agent. Through downloading the .exe file and placing the configuration files in the right location or the easy option. Downloading the .msi and going through the installation wizard. Whichever method you prefer, you'll first have to navigate to the Zabbix download page. We will be using the .msi in our example.

https://www.zabbix.com/download_agents?os=Windows

Here you will be presented with the choice to download either Zabbix agent or Zabbix agent 2. Choose whichever one you would like to install, but by now we recommend Zabbix agent 2 as it is stable and includes more features.

Once downloaded, we can open the new zabbix_agent2-x.x.x-windows-amd64-openssl.msi file and it will take us to the wizard window.