Zabbix 6 host connection problems

[Support IT]

Hi,
I get the following error about zabbix agent availability: ''Get value from agent failed: ZBX_TCP_READ() failed: [104] Connection reset by peer".
Zabbix server version is 6.0.6 on a debian 11 and the agents are on windows 10 machines.
I am also able to telnet from both sides on ports 10050,10051.
SNMP agents lost too and i cant seem to understand why, so any help would be appreciated

[vladimir_lv]

Hi!
There are some reasons why you get such an error:

1. Zabbix agent closes the connection because it comes from a host or IP address, not matching "Server=" parameter in zabbix_agentd.conf file.
2. If you have used encryption, so check your TLS settings
3. Some network device (firewall) between server and agent is disrupting communication.

[vladimir_lv]

Hi!
There are some reasons why you get such an error:

1. Zabbix agent closes the connection because it comes from a host or IP address, not matching "Server=" parameter in zabbix_agentd.conf file.
2. If you have used encryption, so check your TLS settings
3. Some network device (firewall) between server and agent is disrupting communication.

[Support IT]

Hi,
Thanks for your suggestions.
It is my debian VM (on ESXi host) that was causing the problem (Zabbix runs on Debian OS). Although i have assigned a static ip address, there is a second one from dhcp even though i have only one network interface. Still haven't figured out where is coming from...
Once i added this second ip to "Server=" parameter in zabbix_agentd.conf, agents began to show up.