Update to Zabbix Server 7.0.19

[osk_dt]

We've updated to Zabbix Server 7.0.19 but right after the update, we had all of our passive clients in our DMZ fail to communicate. We've confirmed the port 10050 is open from the Zabbix server to the clients. We've confirmed the clients are all on agent2 version 7.0.19 as well. Once we revert back to 7.0.18, we're able to communicate with our passive clients in the DMZ. Anyone else seen this? We didn't see anything explicit in the release notes.
Thank you,

[osk_dt]

Update: I thought the issue might be related to PSK encryption, but once that was configured, I could use zabbix_get on the command line to get data from one of the clients, but it didn't work from the web interface. I tried updating the host items in the web interface and still no data. I used https://www.zabbix.com/documentation...re_shared_keys to configure the keys on both server and client. This is how I was able to get zabbix_get to work from zabbix_server.

[osk_dt]

Update: We’ve identified an issue related to the recent Zabbix update (from 7.0.18 to 7.0.19). It appears that the update caused unexpected behavior affecting clients located in our DMZ. These clients have restricted communication settings—Zabbix can only reach them if it initiates the connection.

Here’s what’s happening:

• Once we updated the Zabbix server, it forced all clients to auto-register.
• During the auto-register, the DMZ client responds to Zabbix with the firewall's internal (NAT) IP.
• For some reason, Zabbix is now interpreting this NAT IP as the client’s actual interface IP and replacing the correct IP in its records.
• As a result, subsequent ping attempts from Zabbix to the client fail, since the NAT IP is configured to drop ICMP echo requests.
• Additionally, we do not want Zabbix to use the NAT IP for monitoring purposes.

Prior to the update, we did occasionally see the NAT IP appear in the client’s configuration, but it never replaced the actual IP. The current behavior represents a significant change and is impacting monitoring functionality.

It's possible, this link addresses some of the issues: https://support.zabbix.com/browse/ZBX-20207