From a new terminal window launch the following command:
sudo snmpconf -g basic_setup
When prompted, enter your administrator password, and follow the on screen prompts to configure SNMP depending on your requirements. Once you have completed the configuration launch the following command from the terminal window
sudo launchctl load -w /System/Library/LaunchDaemons/org.net-snmp.snmpd.plist
That’s it, all being well you should now have SNMP enabled on your OS X machine.