[vortex] store-and-forward mode

Bogdan Costescu bogdan.costescu@iwr.uni-heidelberg.de
Thu Mar 6 06:20:01 2003


On Wed, 5 Mar 2003 i4onfmn02@sneakemail.com wrote:

> According to my network administrators, this is because the 3C920 is
> known to send corrupt data on interface shutdown when it's not in
> store-and-forward mode, which I'd never heard of before.

Neither did I, for a NIC. Store-and-forward is commonly used when 
referring to switches which load the whole packet in memory before 
directing it to another port (or broadcast it) - this way the switch can 
check the integrity of the packet and keep a healthy network.

Another thing which I never heard of is card sending data on interface 
shutdown. The card itself doesn't care about shutdown - if data is queued 
for transmission, the driver/card tries to send it, but the driver/card 
never generates any data. The only problem here might be wrongly set media 
type and speed which might create sometimes corrupted packets. But this is 
a (human) configuration error... And it's not related to shutdown, it can 
happen for any packet that is sent.

> On that note, does anyone know how to manually turn on store-and-forward
> mode?

For most switches, this is the only mode supported, so it can't be 
turned on or off.

-- 
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