Paperback 
Install Zabbix Agent on Ubuntu on Same Network as Zabbix Server
Video Lecture
Description
I install Zabbix Agent on an Ubuntu 20.04.
I first need to download and install the repository on the server.
The page with these instructions are at
https://www.zabbix.com/documentation/current/manual/installation/install_from_packages/debian_ubuntu
wget https://repo.zabbix.com/zabbix/5.0/ubuntu/pool/main/z/zabbix-release/zabbix-release_5.0-1+focal_all.deb
dpkg -i zabbix-release_5.0-1+focal_all.deb
apt update
After that, I then run
sudo apt install zabbix-agent
Now to configure the agent,
sudo nano /etc/zabbix/zabbix_agentd.conf
Edit parameters for Server, ServerActive and Hostname and save.
Then,
sudo service zabbix-agent start
sudo service zabbix-agent restart
Now to configure a new host on the Zabbix Server itself.
After that,
then go back to the server with the new agent and restart the agent
sudo service zabbix-agent restart
If Zabbix server is reporting an error about connection failure, you can check the zabbix agent log file using
tail -f /var/log/zabbix/zabbix_agentd.log
Zabbix 5.2
Ubuntu 20.04 Focal
wget https://repo.zabbix.com/zabbix/5.2/ubuntu/pool/main/z/zabbix-release/zabbix-release_5.2-1+ubuntu20.04_all.deb
dpkg -i zabbix-release_5.2-1+ubuntu20.04_all.deb
apt update
sudo apt install zabbix-agent
Ubuntu 18.04 Bionic
wget https://repo.zabbix.com/zabbix/5.2/ubuntu/pool/main/z/zabbix-release/zabbix-release_5.2-1+ubuntu18.04_all.deb
dpkg -i zabbix-release_5.2-1+ubuntu18.04_all.deb
apt update
sudo apt install zabbix-agent
Centos 8
rpm -Uvh https://repo.zabbix.com/zabbix/5.2/rhel/8/x86_64/zabbix-release-5.2-1.el8.noarch.rpm
dnf clean all
dnf install zabbix-agent
Centos 7
rpm -Uvh https://repo.zabbix.com/zabbix/5.2/rhel/7/x86_64/zabbix-release-5.2-1.el7.noarch.rpm
yum clean all
yum install zabbix-agent
Zabbix 5.0
Ubuntu 20.04 Focal
wget https://repo.zabbix.com/zabbix/5.0/ubuntu/pool/main/z/zabbix-release/zabbix-release_5.0-1+focal_all.deb
dpkg -i zabbix-release_5.0-1+focal_all.deb
apt update
apt install zabbix-agent
Ubuntu 18.04 Bionic
wget https://repo.zabbix.com/zabbix/5.0/ubuntu/pool/main/z/zabbix-release/zabbix-release_5.0-1+bionic_all.deb
dpkg -i zabbix-release_5.0-1+bionic_all.deb
apt update
apt install zabbix-agent
Ubuntu 16.04 Xenial
wget https://repo.zabbix.com/zabbix/5.0/ubuntu/pool/main/z/zabbix-release/zabbix-release_5.0-1+xenial_all.deb
dpkg -i zabbix-release_5.0-1+xenial_all.deb
apt update
apt install zabbix-agent
Centos 8
rpm -Uvh https://repo.zabbix.com/zabbix/5.0/rhel/8/x86_64/zabbix-release-5.0-1.el8.noarch.rpm
dnf clean all
dnf install zabbix-agent
Centos 7
rpm -Uvh https://repo.zabbix.com/zabbix/5.0/rhel/7/x86_64/zabbix-release-5.0-1.el7.noarch.rpm
yum clean all
yum install zabbix-agent
Zabbix 4.4
Ubuntu 20.04 Focal
wget https://repo.zabbix.com/zabbix/4.4/ubuntu/pool/main/z/zabbix-release/zabbix-release_4.4-1+focal_all.deb
dpkg -i zabbix-release_4.4-1+focal_all.deb
apt update
apt install zabbix-agent
Ubuntu 18.04 Bionic
wget https://repo.zabbix.com/zabbix/4.4/ubuntu/pool/main/z/zabbix-release/zabbix-release_4.4-1+bionic_all.deb
dpkg -i zabbix-release_4.4-1+bionic_all.deb
apt update
apt install zabbix-agent
Ubuntu 16.04 Xenial
wget https://repo.zabbix.com/zabbix/4.4/ubuntu/pool/main/z/zabbix-release/zabbix-release_4.4-1+xenial_all.deb
dpkg -i zabbix-release_4.4-1+xenial_all.deb
apt update
apt install zabbix-agent
Centos 8
rpm -Uvh https://repo.zabbix.com/zabbix/4.4/rhel/8/x86_64/zabbix-release-4.4-1.el8.noarch.rpm
dnf clean all
dnf install zabbix-agent
Centos 7
rpm -Uvh https://repo.zabbix.com/zabbix/4.4/rhel/7/x86_64/zabbix-release-4.4-1.el7.noarch.rpm
yum clean all
yum install zabbix-agent
Troubleshooting Agent Setup
Ensure your hostname in the Zabbix UI matches the Hostname in the agents config file.
For passive checks, the Zabbix server should be able to ping the agent by the ip address or domain name you set up in the host configuration interface fields. And that you can telnet, from the Zabbix server (or Zabbix Proxy, if configured to use a proxy), to the port (default 10050), that the agent process is listening on.
For active checks, the server with the agent running, should be able to ping the ip address, or domain name you've set in the ServerActive parameter in the agents configuration file. This address will be the Zabbix Server, and/or the Zabbix Proxy. It should also be able to telnet to the Zabbix Server/Proxy port (default 10051)
To read the Zabbix Agent log files on the host,
tail -f /var/log/zabbix/zabbix_agentd.log
tail -f /var/log/zabbix/zabbix_server.log