Adding Windows Host into Zabbix (Active Check Mode)

1. Download Zabbix Agent

Make sure you are using same version as your Zabbix server.

https://www.zabbix.com/download_agents

I am using Zabbix 4.0 LTS, so here is my download link for Windows Agent:
https://www.zabbix.com/downloads/4.0.17/zabbix_agent-4.0.17-windows-amd64-openssl.msi
https://www.zabbix.com/downloads/4.0.17/zabbix_agent-4.0.17-windows-i386-openssl.msi

2. Install Zabbix Agent

By default, it will install your agent as passive mode

2.1 Verify ports

For passive mode:
C:\Users\John>netstat -na | find "100"
TCP 0.0.0.0:10050 0.0.0.0:0 LISTENING
TCP [::]:10050 [::]:0 LISTENING

For both passive and active mode:

C:\Users\John>netstat -na | find "100"

TCP 0.0.0.0:10050 0.0.0.0:0 LISTENING

TCP 192.168.2.31:49524 34.67.224.10:10051 TIME_WAIT

TCP [::]:10050 [::]:0 LISTENING

For Avtive mode only:

C:\Users\John>netstat -na | find "100"

TCP 192.168.2.31:49688 34.67.224.10:10051 TIME_WAIT

2.2 Enable Active mode:

Wordpad edit C:\Program Files\Zabbix Agent\zabbix_agentd.conf. Find the section relating to ServerActive:

### Option: ServerActive

# List of comma delimited IP:port (or DNS name:port) pairs of Zabbix servers and Zabbix proxies for active checks.

# If port is not specified, default port is used.

# IPv6 addresses must be enclosed in square brackets if port for that host is specified.

# If port is not specified, square brackets for IPv6 addresses are optional.

# If this parameter is not specified, active checks are disabled.

# Example: ServerActive=127.0.0.1:20051,zabbix.domain,[::1]:30051,::1,[12fc::1]

# Mandatory: no

# Default:

# ServerActive=

ServerActive=34.67.224.10

2.3. Disable Passive check:

Change StartAgents value to 0.

### Option: StartAgents
# Number of pre-forked instances of zabbix_agentd that process passive checks.
# If set to 0, disables passive checks and the agent will not listen on any TCP port.
#
# Mandatory: no
# Range: 0-100
# Default:
# StartAgents=3

StartAgents=0

Remove following default passive related Server= settings.

### Option: Server
# List of comma delimited IP addresses, optionally in CIDR notation, or DNS names of Zabbix servers and Zabbix proxies.
# Incoming connections will be accepted only from the hosts listed here.
# If IPv6 support is enabled then '127.0.0.1', '::127.0.0.1', '::ffff:127.0.0.1' are treated equally and '::/0' will allow any IPv4 or IPv6 address.
# '0.0.0.0/0' can be used to allow any IPv4 address.
# Example: Server=127.0.0.1,192.168.1.0/24,::1,2001:db8::/32,zabbix.domain
#
# Mandatory: yes, if StartAgents is not explicitly set to 0
# Default:
# Server=

### Option: ListenPort
# Agent will listen on this port for connections from the server.
#
# Mandatory: no
# Range: 1024-32767
# Default:
# ListenPort=10050

2.4 Make New Templates with 'Zabbix Agent (active)'

Before I start changing hosts from passive to active checks, I needed to
make three new templates-objects. For each of
'Template App Zabbix Agent', 'Template OS Linux' and
'Template App MySQL', do:

- Go to Configuration : Templates, select template $name
- scroll down, click 'Full Clone'. Change the clone's name to "$name
Active" and click 'Add' at the bottom.
- In Configuration : Templates, Find the new "$name Active" template,
click on the 'Items' item on its row.
- Click on the checkbox in the upper-left to select all rows, scroll
down to the drop-down and select 'Mass Update' and click 'Go'
- Click the checkbox for 'Type' and select 'Zabbix Agent (active)' in
the dropdown that appears. Scroll down and click the 'Update' button.