Net-SNMP configuration for non-root AgentX application

It is imperative to run the application when developing it. You may be testing it, debugging it or troubleshooting something. By default Net-SNMP uses named socket for AgentX communication which does not allow a non-root user to connect making troubleshooting difficult. There are security reasons for not allowing this kind of widely open access so do not set this up in your production environment. There are other ways to control the access which I will narrate in future posts.

To enable AgentX and allow non-root applications/Agents to connect to snmpd you can setup TCP socket as follows. TCP socket provides a cleaner access and allows easier troubleshooting e.g you could capture network traffic between snmpd and the AgentX application. Update /etc/snmp/snmpd.conf and ensure that following directives are set for TCP based AgentX communication.

rocommunity public default # or whatever community string/access control you want
master agentx # Run as an AgentX master agent
agentXSocket tcp:localhost:705 # Listen for localhost network connections instead of /var/agentx/master

Restart snmpd (/etc/init.d/snmpd restart)

Alternate is to set correct permissions for /var/agentx/master named socket or whatever you have configured.