Strange network behaviour

[Lowell Gilbert]

Vincent Zee <basics at zenzee.cistron.nl> writes:

> I am really at a loss at the moment.
> 
> I have a 100baseT network at home and all connected machines have 100Mb 
> network cards.
> When I upload mp3 files from my ibook to the FreeBSD server the speed 
> drops to 100kb/s.
> 
> This only happens between these two particular machines. These same 
> machines connected to other machines give the expected transmission 
> speeds. I checked cables, switches and router but found nothing 
> unexpected.
> 
> Any hints, ideas or even solutions are most welcome.
> 
> The FreeBSD machine is running 4.7 and the ibook 10.2.4

This sounds a lot like a duplex mismatch. 
Check the collision count.