How to Configure Zabbix Monitoring for Windows Server with NAT and iptables

Environment

Zabbix server interfaces: ens192 10.127.0.133, ens256 172.168.0.2.

Windows Server 2012 interfaces: ens192 172.168.0.3, gateway 172.168.0.2.

Configure Shared Internet and Port Forwarding

The Windows Server runs as an ESXi VM; because public IPs are scarce, NAT is performed on the Zabbix server using iptables.

Enable Routing on Zabbix Server

echo 1 > /proc/sys/net/ipv4/ip_forward

or edit /etc/sysctl.conf and add net.ipv4.ip_forward = 1, then run sysctl -p.

iptables Configuration

iptables -t nat -A POSTROUTING -s 172.168.0.0/24 -o ens192 -j SNAT --to-source 10.127.0.133
iptables -t nat -A PREROUTING -d 10.127.0.133 -p tcp --dport 3389 -i ens192 -j DNAT --to-destination 172.168.0.3:3389
iptables-save

Test Network Connectivity

Remote Connection Test

Enable the Remote Desktop role on Windows Server 2012, then connect to the internal Windows host via the Zabbix server’s port 3389.

Download Zabbix Agent Client

Download URL: https://assets.zabbix.com/downloads/4.2.6/zabbix_agent-4.2.6-win-amd64-openssl.msi

Installation Steps

Agent Service Starts Automatically

Port 10050 Listening

Add Windows Host in Zabbix

Enter the Windows host name; initial connection may fail with error 104 because iptables rules are ordered incorrectly.

get value from agent failed: ZBX_TCP_READ() failed;[104] connection reset by peer

Place the correct NAT rule at the top of the chain:

iptables -t nat -I POSTROUTING -d 172.168.0.0/24 -p tcp -m tcp --dport 10050 -j SNAT --to-source 10.127.0.133
iptables-save

After reloading, the agent status becomes "available”.

Zabbix provides a Windows monitoring template that discovers services and offers many built‑in items.

Example Windows Monitoring Items

Monitor IIS Process Status

Use the proc.num[] key to count processes; configure a trigger when the count is zero.

Monitor IIS Concurrent Connections

Add a performance counter for IIS connections under the Web Service path; other IIS metrics (e.g., CGI request count) can be added similarly.

Feel free to comment and discuss any questions.