[vortex] HELP needed: Cross-over connection to Router not working with 3c509C (Tornado)

Bogdan Costescu bogdan.costescu@iwr.uni-heidelberg.de
Fri Feb 7 09:13:01 2003


On Thu, 6 Feb 2003, [iso-8859-1] Cristian Alonso wrote:

> But when I try to connect the router and the PC (without using a HUB)
> with a cross-over cable, link indicators look up, but I am not able to
> send/receive any traffic from the PC or the router (IP configuration is
> OK).

What does /proc/net/dev show ? Does the number of interrupts associated 
with the device increase in /proc/interrupts ?

> until I asked 3COM support and they told me to change the PHYCOMPAT
> field in ther Windows driver and voila!, the cross-over connection
> started to work fine.

I have just checked on a Windows 2000 computer and indeed this setting was 
there - it was enabled and I'm sure that I haven't touched it before, so 
this might be the default. After disabling it, I was still able to use the
computer. A search in the documentation and 3Com site returned nothing, a 
search on the Internet only returned some .INF files that contained it as 
an entry. So, I have no idea what it is about.
If 3Com support can indicate to you what this option does (maybe even what 
registers on the card are modified, although I doubt this), it might 
provide us with some clue about a Linux equivalent.

Could you check if this card is really a 905C or a 905CX (Windows driver 
might report it with the correct name, best is to open the computer and 
look at what's written on the card) ?

Do you have any other computer preferrably with a different NIC ? You 
could then check if connecting this computer to the router with the same 
crossover cable works and even if connecting the 2 computers with this 
crossover cable works and you need or not to activate this option in the
Windows driver. I ask this because I suspect the cable to not be 
good; I routinely connect with crossover cables computers with 3Com cards 
and I never had any problems.

-- 
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