AP is not processing all SNMPv3 messages. They show up in Wireshark trace

Products

• Automation Point

Issue/Introduction

SNMPv3 Being received in Wireshark trace but AP is not processing the SNMPv3 messages

We believe this is due to an ongoing issue with AP interacting with NETSNMP and somehow the messages are not authenticating correctly.

The Server is seeing the SNMPv3 traffic, but AP is intermittently not seeing the SNMPv3 traffic.

In the packet capture where we were monitoring SOLSYSD, we see the traffic hitting wireshark but intermittently not getting to AP 

Resolution

The packet not recognized by NET-SNMP was fragmented on the way, as seen in the log: 

           [2 IPv6 Fragments (1741 bytes) #99203(1448), #99204(293)]

CISCO elements are by default configured to fragment SNMP packets over 1500B, which happened here.

Either limit the packets under 1500B or configure the network element(s) to allow greater packets will resolve the problem.

Additional Information

If this does not help resolve the issue, open a support case and provide the APDiag along with an example of the packet capture from where the packet is not received by AP.