Fedora Tips

2004-02-11 Fedora Tips 41:
This tip is very useful for users of motherboards with Sysconnect or 3Com 1Gbit ethernet card.

People have a problem with those cards and for now there was no solution. I found one.

Problem description:

1. Using 3Com's 3c2000.o driver (downloaded from ASUS site for 3C940 chipset) one cannot connect to sshd or vnc server on Fedora box from windows clients (from linux everything went ok). Moreover, some cannot even browse some web addresses (like linuxnew.com.pl).

2. I found that 3C940 chipset is almost the same as SysConnect chip, so I used the sk98lin.o driver which comes as default module compiled with standard Fedora kernel. The things changed. One can conect from any windows ssh or vnc client but I get flood of kernel messages like:

30 messages suppresed
Neighbour table overflow

in the console. Mozilla sometimes cannot load new page, I had to reload a few times to get result. I found in the internet that this chip has a hardware bug which gets TX checksum error when a packet is shorter than some bytes (54 if I remember), and that newest sk98lin driver fix this.

3. I downloaded the newest SysConnect sk98lin driver from their site. After compilling and rebooting the problem persists.

Problem solution:

4. I turned on HalfDuplex mode of my Ethernet card (default is FullDuplex. THE PROBLEMS ARE GONE.

I don't know if this sollution works only with the newest SysConnect driver. Maybe it works also with odler sk98lin.o or 3Com's 3c2000.o, but I have no time to test it. The good part is that now everything works well. - submitted by Darek Borkowski