[vortex-bug] Re: 3c59x 0.99H and 3c905B (Cyclone) problems

Bob Ramstad rramstad@alum.mit.edu
Fri, 4 Aug 2000 16:22:33 -0400

i have found the solution to my problem.

thank all of you for your time and suggestions.  i did try many of
them -- and in fact, tried a lot more of them before sitting down and
reflecting on all the stuff i had tried and then making a list of
every possibility i could think of that hadn't been tried, and then
systematically going through those.

the problem was caused by a bad or possibly intermittant patch cable.

i made many assumptions because the card worked flawlessly in 10 mbps
mode but would not work properly in 100 mbps mode.  in particular, i
assumed that the physical media to the switch in the network closet
MUST be good, since it's been working for months in 10 mbps mode.

it's good to be humble, and i'm glad that the solution has been found.

i would like to thank "Winged Wolf" for suggesting that the card might
be bad.  this suggestion was incorrect, but it did lead me to a
complete rethink of the whole process, especially the hardware end of

while i do feel bad for "crying wolf" and potentially wasting a lot of
folks' time, on the other hand, i know i've learned something.  it IS
possible to have a cabling problem that doesn't show up at 10 mbps
which does show up at 100 mbps.  maybe this is a function of the
driver -- perhaps it quietly gives up when the media is bad? -- or
maybe it's just a function of the weirdo flaky cable i've got here, or
the switch, or the combination of switch and card... but this is just
about the weirdest thing i've seen.  my jaw hit the floor when i
swapped cables and it started working... and i was even more surprised
when i put the bad cable back in and it stopped working again, but
then worked in 10 mbps mode...

-- Bob