"Sampsa" == Sampsa Laine <sampsa at mac.com> writes: If you have other FDDI devices that also have A or B ports, just plug A to B in a circular fashion, and you have a dual ring. This is the topology that FDDI originally started with early in its development. Sampsa> So if I have two dual port PCI cards, one in machine 1, one Sampsa> in machine 2, I wire them: Sampsa> 1.A. -> 2.B 2.A -> 1.B Sampsa> To create a circle? Do I HAVE to do this, i.e. can I just Sampsa> wire one cable between machine 1 and 2 (the cables are Sampsa> EXPENSIVE, like 3x what the adapter cost me)? One connection is fine. As I mentioned, the standard topology for A/B stations (Dual Attached stations) is A to B in a circular fashion. That creates a pair of rings. And that topology can handle single faults: the loss of a single port or single cable. If you just connect the two stations with a single cable, what you created is a dual ring with a single fault -- one of the two cables is missing. That will work just fine. paul