[e2e] packet loss in the Internet

Rick Jones rick_jones2 at hp.com
Fri May 24 11:09:37 PDT 2002

Stefan Savage wrote:
> I agree about congestion.  However, I've measured significant loss in
> enterprise networks on several occasions that arose from Ethernet
> full-duplex/half-duplex conflicts (its still not clear to me if the
> Ethernet autonegotiation protocol is fundamentally inadequate or if
> current implementations are simply poor).  Its unclear to me how
> prevalent this problem is, but I've run into it in three separate
> networks.

My anecdotal experience is that today these duplex mismatches stem not
from problems in contemporary autoneg gear, but from people still
thinking that AutoNeg is completely fubar, and not being consistent in
_always_ "hardcoding" _both_ sides _everywhere_ to the same setting.
Often as not they think that hardcoding one side is enough - they do not
realize that autoneg "fails" when one side is hard coded. Or, not all
ports on a switch are set the same and someone moves a cable from one
port to another. Or someone installs a system and forgets to configure
the hardcode.

Again it is only (limited) anecdotal, but I supsect that today's kit has
autoneg more robust than the admins.

rick jones
Wisdom Teeth are impacted, people are affected by the effects of events.
these opinions are mine, all mine; HP might not want them anyway... :)
feel free to post, OR email to raj in cup.hp.com  but NOT BOTH...

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