Please review and merge:
https://github.com/OpenNMS/opennms/pull/139

The handling of null-values while (de-)serializing the snmp agent config was still clumsy. This seems to affect all cases, where values are set to null but have a default.

If a default value exists, the key-value pair is skipped during serialisation. During deserialisation, an object with default values is created and the serialized changes are applyed afterwards.

The following pull-request contains a fix for the problem by creating an object during deserialisation without having any default-values set:
https://github.com/OpenNMS/opennms/pull/139

Have a look at https://opennms.atlassian.net/browse/NMS-6860#icft=NMS-6860. There NRTG seems to work with SNMP v3. Any ideas?

SNMP v2 and v3 data collection works like a charm. NRTG using SNMP v2 also works very well. Only the combination NRTG using SNMP v3 does not show any data.

Im using the following commit:
04c12468770e6ad779d9e4589136784096329baf

Some steps to reproduce the problem:

1. Create a SNMPv3
   usernet-snmp-create-v3-user -ro opennms

1. Update the snmp-config.xml
   cat > etc/snmp-config.xml << EOF
   <snmp-config xmlns="http://xmlns.opennms.org/xsd/config/snmp" version="v2c" read-community="republic" timeout="1800" retry="1">
   <definition security-name="opennms" security-level="2" auth-passphrase="test1234" auth-protocol="MD5" version="v3" port="161">
   <specific>127.0.0.1</specific>
   </definition>
   </snmp-config>

1. Restart OpenNMS
   ./bin/opennms restart

Then login to the UI - check if SNMP is working (poller is up), datacollection works (waite some time - graphs should have some data).

The go to resource graphs and open NRTG graph for i.e. load - No values are recieved...

Hey Dustin,

please provide more information.

I tested this a couple of days ago and it worked.