[vortex] 3c905C: Packet losses, but only with a switch

[Giuseppe Ciaccio]

Hello,

I recently purchased two 3COM 3c905C adapters, and tested them under
Linux 2.2.13 with driver 0.99H .  In order to avoid any negotiation-related
problems, I explicitly set up the media type and duplexness using the
3c90xcfg.exe config program (under DOS).

Then, I connected the two NICs by an Intel Express 510T switch.
The switch is manageable, and I explicitly programmed the duplexness of
each port to match the NIC duplexness.

The result:
very frequent packet losses using "ping -f", with half-duplex as well as
full-duplex.

The problem does not occur if a crossover cable is used in place of the switch.
The problem does not occur as well, if other NICs (DEC DE500, 3COM 3c905 with
same device driver) are used in place of the 3c905C adapters.

Is it a bug in the NIC firmware?
Has anybody experienced similar odd behaviours with this NIC?
Has anybody any idea of what's going on?
Shall I have to resell my NICs to somebody else? :(

Thank you,
Giuseppe


Giuseppe Ciaccio               http://www.disi.unige.it/person/CiaccioG/
DISI - Universita' di Genova   via Dodecaneso 35   16146 Genova,   Italy
phone +39 10 353 6638          fax +39 010 3536699 ciaccio@disi.unige.it
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