Dear Filipp,
Thanks once more for providing the pointers. I tried some manual SNMP get requests via the CLI again, from our NetXMS server, and they were succeeding. I tried the full configuration poll once more, and it failed again.
Next I started looking at the NetXMS full configuration poll and at the manual SNMP get requests in wireshark. I was filtering on the destination device IP and noticed that while the manual requests are successful, I only see the get requests when filtering my pcap on destination IP, I don't see the responses. Then it finally dawned on my: because these are L3 switches and the IP we use to manage them is in a different subnet, the L3 switches are sourcing their SNMP response from the IP they have in the NetXMS subnet.
I need to solve this with some SNMP source configuration.
So the last mystery was why are manual requests succeeding and NetXMS requests failing? It looks like the snmpwalk and snmpget from Net-SNMP are able to recognize the responses based on their query ID, even though the response comes from a different IP. NetXMS does not accept this, which is arguably cleaner and safer.
Thanks again for helping me figure this out. This topic can be closed as the root cause is identified.
			Thanks once more for providing the pointers. I tried some manual SNMP get requests via the CLI again, from our NetXMS server, and they were succeeding. I tried the full configuration poll once more, and it failed again.
Next I started looking at the NetXMS full configuration poll and at the manual SNMP get requests in wireshark. I was filtering on the destination device IP and noticed that while the manual requests are successful, I only see the get requests when filtering my pcap on destination IP, I don't see the responses. Then it finally dawned on my: because these are L3 switches and the IP we use to manage them is in a different subnet, the L3 switches are sourcing their SNMP response from the IP they have in the NetXMS subnet.
I need to solve this with some SNMP source configuration.
So the last mystery was why are manual requests succeeding and NetXMS requests failing? It looks like the snmpwalk and snmpget from Net-SNMP are able to recognize the responses based on their query ID, even though the response comes from a different IP. NetXMS does not accept this, which is arguably cleaner and safer.
Thanks again for helping me figure this out. This topic can be closed as the root cause is identified.