Foraward SNMP requests from Agentx Master to Agentx Subagent

Question

I am running an agentx master and an agentx subagent on linux. When I run snmpget on a default MIB i.e. sysdescr.0 it returns fine, but when I request for a MIB that was registered through the agentx subagent it timesout. It appears that the master receives the GET request but does not forward on to the agentx subagent. The MIB is registered successfully but when master agentx receives the GET request it saying "Sending 60 bytes to UDP: unknown". It can't find the location to forward to.

Am I missing a configuration of some sort on the subagent side? How does the master know who is suppose to receive the requests?

Answer 1

TCP port 705 is used by default for AgentX protocol. Master agent listens on this port and subagents send registrations to this port - master agent then knows who is registered.

You did not mentioned it, do you use net-snmp? If so, see the Agent FAQ 12 - How can I run AgentX with a different socket address?.

Answer 2

Thanks for the response. I am using net-snmp. Also, I am using udp and I have changed the port to be 10161 for agentx protocol. Both apps come up and initialize fine on the new port. I can see the "ping" messages going back and forth to communicate with each other. So the connection seems fine, but when I run snmpget on another machine and query for the MIB, the master says the address is unknown to where it should be forwarded to. It doesn't know what subagent it should sent it off to.