Good advice, but I'll add that there are many bad things smokeping won't detect. My favorites are APs/range extenders/meshes that don't do multicast properly (

Good advice, but I'll add that there are many bad things smokeping won't detect. My favorites are APs/range extenders/meshes that don't do multicast properly (mDNS in particular, breaking lots of LAN-based apps), and also ones that seem to semi-randomly isolate devices (i.e., prevent devices connected to the AP from reaching devices that are not connected to it, except the gateway). There are a huge number of these devices (I'm looking at you, Netgear). Sometimes ICMP will work, but not TCP. It's nightmarish to debug, because it often seems to be some table-size issue in the AP, so devices will work for a while, and then some new device connects and the old ones break.