Oversized Ethernet Frame?

Holger Metschulat homer@sgs.wh.tu-darmstadt.de
Thu Dec 16 19:32:49 1999


Hi,

we are using 3 ATI cards with the RTL8139 chip in a firewall. To do this, I
had to set down the ring buffer size (RX_BUF_LEN_IDX) to 32k because
otherwise the system could not allocate enough memory (is that okay?).

Sometimes, especially when transmitting larges files with ftp through the
firewall, the _egress_ card (the card that outputs the ftp data frames, the
downstream side of the firewall) crashes with an oversized frame message:

Dec 11 17:45:02 fsz-gw kernel: eth0: interrupt  status=0x0001 new intstat=0x0000.
Dec 11 17:45:02 fsz-gw kernel: eth0: In rtl8129_rx(), current 7300 BufAddr 0088, free to 72f0, Cmd 0c.
Dec 11 17:45:02 fsz-gw kernel: eth0:  rtl8129_rx() status bc3a6ebb, size bc3a, cur 7300.
Dec 11 17:45:02 fsz-gw kernel: eth0: Frame contents  bb 6e 3a bc 9f 15 37 c3 4e 61 4a 97 dd 1a 4b 25 4e 72 e7 e7 b3 f0 5e 86 42 a1 b1 97 94 d9 32 d8 38 72 72 ff bd ec 41 a6 ae 37 7d 0a 70 6e ca e1 94 44 35 70 ef f3 d9 ad 63 fa 79 6e 76 99 b1 67 6d b7 1b 6f 39 c1.
Dec 11 17:45:02 fsz-gw kernel: eth0: Oversized Ethernet frame, status bc3a6ebb!
Dec 11 17:45:02 fsz-gw kernel: eth0: Done rtl8129_rx(), current 2f40 BufAddr 0088, free to 2f30, Cmd 0d.
Dec 11 17:45:02 fsz-gw kernel: eth0: interrupt  status=0x0000 new intstat=0x0000.
Dec 11 17:45:02 fsz-gw kernel: eth0: exiting interrupt, intr_status=0x4000000.

As you can see, the driver gets garbage data from the chip (there is not
even a hint on a valid ethernet frame in the logged frame contents). In my
opinion the following problems could be the cause:

- Switch is broken and sends corrupted packet back on line -> Card receives
  garbage.
- Problems in the PCI system -> PCI data transfer between card and mainboard
gets corrupted
- driver problem
- chip problem

The card is then locked, so it has to be reinitialized with ifconfig.

Anyone has a clue?

-- 
Gruss           * Holger Metschulat
  Holger        * e-mail: homer@sgs.wh.tu-darmstadt.de
                * http://www.sgs.wh.tu-darmstadt.de/homer
** Who the hell is General Failure, and why is he reading my hard disk?  **
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