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

[Bogdan Costescu]

On Mon, 3 Jul 2000, Giuseppe Ciaccio wrote:

> 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

These cards (the C revision) are supported correctly from the media
selection point of view only starting with 2.2.15 (with the driver
modified by Andrew Morton) or recent drivers from Donald Becker (0.99Q).
I think that the only relevant portion was adding "HAS_NWAY" to the
definition of 3C905C in the "pci_tbl[]" table. However, newer drivers also
have some other improvements.

> 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.

You should not need to set the duplex type on any end. Donald _always_
says this!

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

...which is quite normal! In the case of the crossover cable, both cards
are going in half duplex mode and stay there (I know exactly because I had
the same situation here about 6 months ago); it's stable as both ends
agree on the speed.

> Shall I have to resell my NICs to somebody else? :(

Nooooo, and please continue to support GAMMA for this NICs!

Sincerely,

Bogdan Costescu

IWR - Interdisziplinaeres Zentrum fuer Wissenschaftliches Rechnen
Universitaet Heidelberg, INF 368, D-69120 Heidelberg, GERMANY
Telephone: +49 6221 54 8869, Telefax: +49 6221 54 8868
E-mail: Bogdan.Costescu@IWR.Uni-Heidelberg.De