i'm trying to setup a zabbix server behind barracuda firewall. Other configurations are working but for some reason this IP is not.
"ZABBIX" on our Barracuda is a service configured in this way:

zabbix service configuration

The barracuda is returning very strange messages. One that the access is a "Normal Operation" and the second one with "Host Access Failure" (click the image to enlarge).

80 normal operation 80 host access denied For me, it is a very strange message, because when i shut my vm down BC is logging "Host Unreachable", so the address is correct.

What could be wrong?

I have disabled UFW (Uncomplicated Firewall) on my Debian (ZABBIX) machine and it is still not working. Additionally, port 22 (SSH) is working perfectly fine, and it is the only one working from outsite https://www.whatismyip.com/port-scanner/ and nmap are showing me only ssh open, 80 and 443 closed. Any tips?


Machine behind Barracuda has only one port open (22 - ssh), but in the service configuration there listed 5 of them :< Online port scanners says that only 22 is open. UFW on Debian says not only ssh, and netstat is also showing more ports

  • 1
    What is not working? What are you trying to do? Monitoring the barracuda from the Zabbix? Accessing the Zabbix interface by a client coming through the barracuda? Monitoring other machines from the Zabbix through the barracuda? It's really not clear. – wazoox Mar 28 '19 at 18:52
  • @wazoox the connection is being dropped. The whatismyip.com/port-scanner says that the 80 port on this server is closed – Toumash Mar 28 '19 at 22:09
  • 1
    Can you access the port 80/443 of the Zabbix machine from the local network? – wazoox Mar 29 '19 at 16:19

We've changed the local IP address of the Barracuda Service and changed the Apaches listen ip from



Listen local.ip:80

The third thing we did was to uninstall iptables (maybe part of the problem)

And it works!

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.