SNMP troubleshooting


We want to monitor a host via snmp and debugging firewall issues. However, we can’t see checkmk sending the snmp over 161. Instead, it’s over random udp ports, so we can’t see 161 in the firewall logs. We have changed it to non inline to see if that makes any difference, but no difference

Can anyone please explain why this is the case or how this works?

Netstat output:

ps output

Why should the source port be 161? This is only the destination port on your monitored device.
The target host is every time reached over 161.

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No the source port isn’t 161. I mean in the firewall log, we can’t see the snmp traffic over 161 (destination). It’s only showing the high port it’s using as the destination for snmp