> > Is it possible an ethernet card accidentally left in promiscuous mode (I
> > think Red Hat's tcpdump is buggy) could cause bad interactions with the
> No tcpdump tends to do this. The RH4 one shouldnt tho.
>
> > NCR SCSI card? I noticed today that eth0 was in promiscuous mode...I
> > often use tcpdump to sniff on this system, but haven't today.
>
> For the ethercard to fall out with the NCR would really require a hardware
> bug like corruption on back to back DMA from different targets - possible
> but improbable and almost impossible to find out
Which kind of back to back DMA do you refer to?
Fast back to back PCI transactions by an initiator with different targets
are only allowed if all targets on the same bus support this feature.
(Some bit set to 1 in the status register).
So, a driver that would set the BACK_TO_BACK bit in the command register
of a PCI initiator would potentially make the BUS unstable if at least
one target does not support this type of fast back to back transactions.
Back to back transactions with the same target normally does not make
problems on a PCI bus and seems not to be an option.
2 PCI transactions separated by an arbitration are not back to back.
I never read that the NCR chips supports fast back to back bit it its
status register.
Gerard.