Simple Check Ping -> confused

[JMAIV]

Hello fellow Zabbix users,

I am facing an issue that is about to make me cry :'( Maybe someone is willing to thing along and point me in the right direction.
I attached a drawing of the current configuration, showing a succesfull ping from the Ubuntu 22.04 box to the Client Device (100.64.0.35)

I can succesfully Ping from the Ubuntu 22.04 serer to the User Device 100.64.0.35 (This is being routed via the IP Sec tunnel)


Then I configured a simple check Ping monitor on the Ubuntu 22.04 server;




Unfortunatly, This does not work as expected. Zabbix is not able to ping the client device.
Result ping 100.64.0.35




As a simple validation for my configuration, I also created a ping monitor for 8.8.8.8 that works without a problem.




So bottom line:
From the Ubuntu 22.04 box I can succesfully ping the 100.64.0.35 client And Google (8.8.8.8)
From Zabbix Simple Check monitoring, I can succesfully monitor pings to Google (8.8.8.8) but not to the client device 100.64.0.35.

What makes this so strange is that I can ping the client device, but Zabbix cannot?

Zabbix details:

zabbix_agentd (daemon) (Zabbix) 5.0.42
Revision e25e9cfa36a 25 March 2024, compilation time: Mar 25 2024 10:11:30

Copyright (C) 2024 Zabbix SIA
License GPLv2+: GNU GPL version 2 or later <https://www.gnu.org/licenses/>.
This is free software: you are free to change and redistribute it according to
the license. There is NO WARRANTY, to the extent permitted by law.

Compiled with GnuTLS 3.7.3
Running with GnuTLS 3.7.3


Thank you in advance for thinking along!

[Markku]

icmppingsec is one of the "simple checks":

https://www.zabbix.com/documentation/current/en/manual/config/items/itemtypes/simple_checks

Zabbix server/proxy is responsible for the processing of simple checks (making external connections, etc).

Since your Zabbix server does not apparently have connectivity to the 100.x host, you have to set that host (where the ping item is configured) to be monitored by a proxy. Then that proxy will make the ping connections.

I usually configure the icmpping items without the target address field and have the ping address configured in the agent interface field, thus having separate host for every ping destination.

Markku