Agents can not talk to Server

[slamanna0212]

Both hosts are Ubuntu Server 24.04
Both hosts are ESXI VMs connected to the same vSwitch
Both hosts are on 10.90.90.0/24
Zabbix Server IP: 10.90.90.45
Agent server IP: 10.90.90.175
Zabbix Version: 7.0.7
Zabbix Agent Version: zabbix_agent2 (Zabbix) 7.0.7

I have setup some Autoregistration rules. I have installed Zabbix-Agent2 on a server with docker running on it. I have restarted the agent service multiple times after placing the config. The agent2 config file is:

PidFile=/run/zabbix/zabbix_agent2.pid
LogFile=/var/log/zabbix/zabbix_agent2.log
LogFileSize=0
Server=10.90.90.45
ServerActive=Server=10.90.90.45
Hostname=AGENT-HOSTNAME
HostnameItem=system.hostname

When I check the agent logs, I see this:

​2025/01/03 23:33:35.001366 [101] cannot connect to [Server=10.90.90.45:10051]: dial tcp: lookup Server=10.90.90.45: no such host
2025/01/03 23:33:35.001398 [101] active check configuration update from host [AGENT-HOSTNAME] started to fail
2025/01/03 23:33:35.001512 [101] cannot connect to [Server=10.90.90.45:10051]: dial tcp: lookup Server=10.90.90.45: no such host
2025/01/03 23:33:35.001523 [101] sending of heartbeat message for [AGENT-HOSTNAME] started to fail

- The agent server can ping the zabbix server and reverse is true.
- If I run a tracepath from either server, The result is one hop, the other server
- I can telnet port 10051 from agent to server and it opens a connection
- I can telnet port 10050 from server to agent and it opens a connection

I am unsure what else to try

[Brambo]

Based on the config shown, You have a HOST with Host Name: "AGENT-HOSTNAME" configured in zabbix? And have the Active agent Linux template setup?
And most important: are you sure that address: "Server=10.90.90.45" is accessible or should that only be 10.90.90.45 (without server= )