Zabbix server on localhost cannot see agent also on localhost

[uagaro]

I am having a strange problem here... It's probably something basic that I am missing, this is my first time using Zabbix and I am just testing.

The setup is rather simple: Only 1 VirtualBox VM running Ubuntu 24.04 with Zabbix server and agent running inside.

These are the things that work:

• I can connect to the webbased interface just fine
• I added the host itself as 127.0.0.1:10050
• By clicking on the host in dashboard I can see diskspace BUT it's not updated (I tested it by writing a large file)

But what doesn't work:

• The host shows as "Not available" in the dashboard.
• When I go to the Hosts-page and hover above the (red) ZBX sign in the "Availability" icon I get the warning:
  127.0.0.1:10050 - "Not Available" - Get value from agent failed: cannot read response: cannot read from socket: [104] Connection reset by peer

Based on that error I checked if it was indeed not available so I did a portscan of 10050 on 127.0.0.1 with nmap, It showed as open.
I then checked what was running on that port with netstat. It was zabbix_agent
I also checked for contents of /etc/zabbix/zabbix_agent2.conf. Hostname, Server and ServerActive were all "vmubutest1" which is the name of the VM (and is known as 127.0.0.1 inside)

So I have no idea what is causing this.

[Markku]

I also checked for contents of /etc/zabbix/zabbix_agent2.conf. Hostname, Server and ServerActive were all "vmubutest1" which is the name of the VM (and is known as 127.0.0.1 inside)

That's your problem then: if your host address (in Zabbix) is 127.0.0.1, the Server directive must be set to 127.0.0.1 (the loopback address) as well.

Also see /var/log/zabbix/zabbix_agent2.log

Markku