[Observium] Auto-discovery Woes

I'm having some major issues with Auto-discovery (read, I can't seem to get it working at all).

Here is what I have in my config:

$config['autodiscovery']['xdp'] = TRUE; // Autodiscover hosts via discovery protocols (CDP, LLDP, FDP, AMAP and other)

$config['autodiscovery']['ospf'] = TRUE; // Autodiscover hosts via OSPF

$config['autodiscovery']['bgp'] = TRUE; // Autodiscover hosts via iBGP

$config['autodiscovery']['libvirt'] = TRUE; // Autodiscover hosts found via libvirt

$config['autodiscovery']['ip_nets'] = array("10.0.0.0/8"); // Networks to permit autodiscovery

$config['discover_services'] = TRUE; // Autodiscover services via SNMP on devices of type "server"

I'm using resolution via hosts file, and I have about 150 machines there. However, autodiscovery seems to do nothing.