> I'm getting this when trying to ping any host on my network > from machine B. > > Which leads me to suspect a problem with my ethernet card. > yet it ifconfigs up and down OK. > > Is there a conclusive test to demonstrate that the problem is > with the network card? Ping your network card. Not the Loop address, but the network address. If you can ping the network address then you should be able to ping the gateway or other systems on your network.
