What is Zabbix? Monitoring basics and your lab

You’ll build two Ubuntu Server 26.04 VMs: zbx01 (192.168.56.80) will run the Zabbix server, MySQL and the frontend, and web01 (192.168.56.81) is the server being watched, with a website and database to monitor in later lessons. Each VM has two network cards: NAT for internet access and Host-only so your laptop and the VMs talk on fixed addresses. Zabbix 8.0 has official packages for Ubuntu 26.04, and 26.04 ships MySQL 8.4, which is the minimum MySQL that 8.0 supports, so stick to 26.04 for this course.

1Check the VirtualBox host-only network

In VirtualBox Manager open File > Tools > Network Manager, Host-only Networks tab. You should see an adapter with IPv4 address 192.168.56.1 and mask 255.255.255.0. If there is none, click Create.

Untick its DHCP server, because the VMs get static addresses.

✅ Checkpoint: A host-only network 192.168.56.1/24 exists and its DHCP server is off.

2Create zbx01

Click New, name it zbx01, choose the Ubuntu Server 26.04 ISO and tick Skip Unattended Installation. Give it 3072 MB RAM, 2 CPUs and a 30 GB disk (Zabbix plus MySQL is happier with 3 GB than 2 GB). Before the first boot open Settings > Network: Adapter 1 attached to NAT, Adapter 2 enabled and attached to Host-only Adapter.

✅ Checkpoint: zbx01 exists with 3 GB RAM, 2 CPUs and two adapters, NAT and Host-only.

3Install Ubuntu Server on zbx01

Start the VM and go through the installer with the defaults. Use hostname zbx01, user student, and tick Install OpenSSH server. Leave the second network card as it is, since netplan sets it next.

When it finishes, remove the ISO, reboot and log in.

Run this on zbx01:

hostnamectl --static
ip -br addr

You should see this (your fe80:: addresses will differ):

zbx01
lo               UNKNOWN        127.0.0.1/8 ::1/128
enp0s3           UP             10.0.2.15/24 metric 100 fe80::a00:27ff:fe3c:51d2/64
enp0s8           DOWN

enp0s3 is the NAT card with the usual VirtualBox address 10.0.2.15, which gives you internet. enp0s8 is the host-only card and has no address yet.

✅ Checkpoint: You are logged in as student on zbx01, and enp0s8 is listed.

4Give enp0s8 a static address with netplan

Paste this whole block on zbx01:

sudo tee /etc/netplan/60-hostonly.yaml >/dev/null <<'EOF'
network:
  version: 2
  ethernets:
    enp0s8:
      dhcp4: false
      addresses: [192.168.56.80/24]
EOF
sudo chmod 600 /etc/netplan/60-hostonly.yaml
sudo netplan apply
ip -br addr show enp0s8

You should see:

enp0s8           UP             192.168.56.80/24 fe80::a00:27ff:fe71:9a0e/64

Netplan files are YAML, so indentation is done with spaces and a single tab breaks the file. The chmod 600 stops netplan warning that the file is readable by everyone.

✅ Checkpoint: enp0s8 on zbx01 shows 192.168.56.80/24 and state UP.

5Update the system and check the clock

Zabbix stamps every value with the server’s time, and trigger functions like “average over the last 5 minutes” depend on it. A VM whose clock drifts gives you odd graphs and confusing alert times, so check it now.

Run this on zbx01:

sudo apt update && sudo apt full-upgrade -y
sudo timedatectl set-timezone Asia/Kolkata
timedatectl

You should see this (your times will differ):

               Local time: Sun 2026-11-08 11:12:40 IST
           Universal time: Sun 2026-11-08 05:42:40 UTC
                 RTC time: Sun 2026-11-08 05:42:39
                Time zone: Asia/Kolkata (IST, +0530)
System clock synchronized: yes
              NTP service: active
          RTC in local TZ: no

“System clock synchronized: yes” means systemd-timesyncd has reached an NTP server through the NAT card. Use your own time zone if you’re outside India; the frontend can show each user their own zone later.

✅ Checkpoint: timedatectl shows System clock synchronized: yes on zbx01.

6Clone web01 and change its identity

Shut zbx01 down (sudo poweroff), right-click it and choose Clone. Name the clone web01, choose Generate new MAC addresses for all network adapters and Full clone, then set its RAM to 1024 MB and 1 CPU. Start web01 only and run:

Run this on web01:

sudo hostnamectl set-hostname web01
sudo sed -i 's/192.168.56.80/192.168.56.81/' /etc/netplan/60-hostonly.yaml
sudo netplan apply
sudo rm -f /etc/machine-id && sudo systemd-machine-id-setup
sudo rm -f /etc/ssh/ssh_host_* && sudo dpkg-reconfigure openssh-server
hostnamectl --static; ip -br addr show enp0s8

You should see this (your fingerprints and fe80:: address will differ):

Initializing machine ID from random generator.
Creating SSH2 RSA key; this may take some time ...
3072 SHA256:p0Xc7v1mQe9RkY2sTn4bWfL8hJd3GzA6uKiN5oVrE1c root@web01 (RSA)
Creating SSH2 ECDSA key; this may take some time ...
256 SHA256:Hq2LwB7xZt0cM4nVyR8eKs1oPf6aJd9UgT3iWlN5bCk root@web01 (ECDSA)
Creating SSH2 ED25519 key; this may take some time ...
256 SHA256:Vm8sQe3rT1yU6iO0pA4dF7gH2jK9lZ5xC8vB3nM1qWe root@web01 (ED25519)
web01
enp0s8           UP             192.168.56.81/24 fe80::a00:27ff:fe0d:44b7/64

A clone carries the same machine ID and SSH host keys as the original. Regenerating them avoids duplicate DHCP leases on the NAT side and “host key changed” warnings when you SSH in later. The hostname matters a lot in Zabbix, because in Lesson 4 the agent on this VM introduces itself as web01.

✅ Checkpoint: web01 has hostname web01, address 192.168.56.81 and a new machine ID.

7Add all lab names to /etc/hosts and test

Start zbx01 again. On both VMs add the four lab names (zbxprx01 and win01 come later, but adding them now saves editing the file twice), then ping across.

Run this on zbx01 and on web01:

printf '%s\n' '192.168.56.80 zbx01 zbx01.lab' '192.168.56.81 web01 web01.lab' '192.168.56.82 zbxprx01 zbxprx01.lab' '192.168.56.83 win01 win01.lab' | sudo tee -a /etc/hosts
ping -c 2 web01

You should see this on zbx01 (your ping times will differ):

192.168.56.80 zbx01 zbx01.lab
192.168.56.81 web01 web01.lab
192.168.56.82 zbxprx01 zbxprx01.lab
192.168.56.83 win01 win01.lab
PING web01 (192.168.56.81) 56(84) bytes of data.
64 bytes from web01 (192.168.56.81): icmp_seq=1 ttl=64 time=0.583 ms
64 bytes from web01 (192.168.56.81): icmp_seq=2 ttl=64 time=0.471 ms

--- web01 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1001ms
rtt min/avg/max/mdev = 0.471/0.527/0.583/0.056 ms

On your laptop, add 192.168.56.80 zbx01.lab to the hosts file too (C:\Windows\System32\drivers\etc\hosts on Windows, opened in Notepad as administrator, or /etc/hosts on Linux and macOS). Then ssh student@zbx01.lab from your laptop should work, which is much nicer than the VirtualBox console.

✅ Checkpoint: zbx01 and web01 ping each other by name, and you can SSH to zbx01.lab from your laptop.

8Confirm the Zabbix 8.0 package exists for your Ubuntu

Before Lesson 2, check that the Zabbix repository has a release package for your exact Ubuntu version. This one check saves a lot of confusion if you installed a different release by mistake.

Run this on zbx01:

. /etc/os-release; echo "$PRETTY_NAME ($VERSION_ID)"
URL=https://repo.zabbix.com/zabbix/8.0/release/ubuntu/pool/main/z/zabbix-release/zabbix-release_latest_8.0+ubuntu$VERSION_ID"_all.deb"
wget -q --spider "$URL" && echo "Zabbix 8.0 package found for Ubuntu $VERSION_ID"

You should see this (after the upgrade in step 5, 26.04.1 or a later point release):

Ubuntu 26.04.1 LTS (26.04)
Zabbix 8.0 package found for Ubuntu 26.04

If the last line doesn’t appear, check the version you installed and your internet access through the NAT card. Notice the /release/ part of the URL: Zabbix 7.0 used repo.zabbix.com/zabbix/7.0/ubuntu/... without it, so old guides copied for 8.0 give you a 404.

Shut both VMs down and take a VirtualBox snapshot of each one called base (select the VM, Snapshots, Take).

✅ Checkpoint: The package check prints “Zabbix 8.0 package found”, and zbx01 and web01 both have a snapshot called base.