[Beowulf] 3com isa and other ethernet adapter : no link

[Robert G. Brown]

On Tue, 7 Sep 2004, Alexandre Abbes wrote:

> Hello
> 
> Thanks for your answer.
>
> But I am sure it is not a 3c59x problem. My pci card wich is a vortex
> boomerang and uses 3c59x.o module works perfectly. I can connect it (on
> the same machine) to my Nvidia adapter which uses forcedeth.o module.
>
> Again, there is a problem with the 3com isa ethernet adapter etherlink
> III (3c509B) that cannot get the link with other ethernet adapters
> different from 3c509B.

This sounds much more likely to be a hardware problem than a software
problem.  For example, the other adapters (or the switch port) on the
segment with it might have very slightly less voltage or current or
slightly shifted timing compared to the 509B.  Not out of spec,
necessarily, but shifted enough so that they won't interoperate.  This
problem might even depend on the host systems in some subtle way --
borderline voltages or browned out power in the hosts might push
periperals to the edge of their operating regimes, an overclocked
bus.

I don't know how one might solve such a problem other than to replace
the offending NICs with ones that are more interoperable (or fix the
electrical power, or overclocking, if it turns out to be that instead).
Fortunately, NICs are cheap, power can be regulated, and overclocking is
a bad idea anyway, if that is in any way involved.

Otherwise I'm fairly clueless.  If the software drivers work at all for
any adapter combination, they ought to work for them all unless the
hardware itself is bent to the edges of the specification.

   rgb

-- 
Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at phy.duke.edu



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