Disable Exponential Backoff (retry) on Ethernet?
julian at elischer.org
Fri Oct 19 17:00:18 PDT 2007
Sten Daniel Soersdal wrote:
> Len Gross wrote:
>> Thanks so much for the response. Here is some additional information.
>> I'm trying to emulate an RF network where there are colisions (e.g.
>> type protocol) so I actually need collisions! I had forgotten that
>> essentially eliminated them. So, lets say I can find/use an "old hub",
>> can I control the number of retries? Maybe I have to find some old
>> NICs and
>> old drivers?
> That would be very NIC specific. Retries are done in NIC hardware as far
> as i know.
> All you need to do to get some collisions is to set the rates to
> half-duplex on both sides (hubs were half-duplex). Hubs with lot's of
> traffic between other hosts would definitely produce more collisions.
> Modern hardware didn't eliminate them. Full-Duplex medium did.
> There is a broad range of full-duplex RF systems too :)
one thing I'd like, that is related, is that if you disconnect a
link for 3 hours it shouldn't sit there using 3000 Mbufs in its output
queue.. how about discarding them....
currently they sit in the queue forwever as far as I can see.
certainly in the em or bce drivers they do..
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