Layer 2 Multicasting problem on shut down system brings down all eepro100's on the net!!

Robert Schwartz roberts@corel.com
Fri Sep 10 14:43:35 1999


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>Donald Becker wrote:
[extracted from below]
>There might be a problem in the RH6.0 system -- the interface is supposed
>to be stopped by the shutdown scripts.  Shutting down the interface should
>stop the EEPro100 completely.

Actually, we also saw the problem on a vanilla Debian 2.1 install when we rmmod'ed
the eepro100 driver, it started to multicast. Even on a straight shutdown with
Debian, we saw it. Its occasional, but there. We'll try the new driver.

Thanks Don!

-Rob

On Fri, 10 Sep 1999, Manfred Young wrote:

>
> > The packets with Ether type 8808 frame are 802.3x link flow control packets.
> > These packets are meant to be used only when the link is in full duplex
> > mode.
> >
> > Unfortunately, the eepro100 driver always enables flow control. Since it's
> > not always possible to determine the duplex setting for a link, I believe
> > that the eepro100 driver should, by default, disable flow control. A new
> > option to enable flow control would then be required.
>
> The chip is documented to generate flow control packets only when it is in
> full duplex mode.  The driver, by default, sets the chip chip to use the
> negotiated duplex.
>
> Since there have been reports that the chip generates Flow Control frames
> even in half duplex mode, the documentation must be wrong.  So I changed the
> driver to only enable FC when it's explicitly negotiated on a full duplex
> link.
>
> The current driver version, v1.09m, includes this change.
>   http://cesdis.gsfc.nasa.gov/linux/drivers/kern-2.3/eepro100.c
>   ftp://cesdis.gsfc.nasa.gov/pub/linux/drivers/kern-2.3/eepro100.c
>
> > > On occasion, after a linux box is halted (we've reproduced it on a Red
> > > Hat 6.0 system running with the stock kernel 2.2.5-15(?)) but the power
> > > remains on, the eepro100 card will start multicasting to mac
> > > destination: 01:80:c2:00:00:01 an Ether type 8808 frame. This, in turn,
> > > causes ALL other eepro100's on the network to pause transmitting,
> > > effectively, crippling all network communications to/from ANY machine
> > > with an eepro100 card on the network!!
>
> There might be a problem in the RH6.0 system -- the interface is supposed
> to be stopped by the shutdown scripts.  Shutting down the interface should
> stop the EEPro100 completely.
>
> Donald Becker                                     becker@cesdis.gsfc.nasa.gov
> USRA-CESDIS, Center of Excellence in Space Data and Information Sciences.
> Code 930.5, Goddard Space Flight Center,  Greenbelt, MD.  20771
> 301-286-0882         http://cesdis.gsfc.nasa.gov/people/becker/whoiam.html

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