In the networking classes I took, we used binary search to determine where a problem was occurring, but with a slight twist: Each step away from the end device

In the networking classes I took, we used binary search to determine where a problem was occurring, but with a slight twist: Each step away from the end device (e.g. workstation, etc.) take two steps upwards in the network. This broadened your scope easily but allowed for very fast refinement of "These are fine, but this is broken".