mike wrote: > Thanks for the reply. > > I've tried that and now this is giving me confusing results: > > A has jumbo frames (mtu 9000) > B has jumbo frames (mtu 9000) > C has normal (mtu 1500) > > B -> A = 3.4MB/sec > C -> A = around 50MB/sec Check to make sure that B is operating in 1000mbps, full duplex, using ethtool, and check to make sure the switch agrees. Duplex mismatches will kill any ethernet link.