Using SNMP4J to retrieve MIB info over TCP instead of UDP

Question

Using the SNMP4J library I am able to successfully retrieve information from multiple agents using SNMP over UDP. I am running into a situation where I need to retrieve information from an agent using SNMP over TCP. The SNMP4J library provides a DefaultTcpTransportMapping class to do this and I believe I've implemented it appropriately. Using Wireshark, I see response packets being returned from the agent running SNMP over TCP but I am getting null response PDUs. What other considerations do I need to address when implementing SNMP over TCP instead of UDP? Any help is greatly appreciated!

After a discussion with the board's manufacturer we've learned that the model for communication is SNMP over PMPP over TCP and I'm working on a custom SNMP4J transport to handle this model.

Answer 1

try to increase timeout value, TCP is slower than udp

UserTarget target = new UserTarget();
target.setTimeout(timeoutInMillis);