Wireshark · Wireshark-users: Re: [Wireshark-users] 8-10% packet error/loss is normal wired network?

[Kok-Yong Tan <ktan@xxxxxxxxxxxxxxxxxxx>]

On 7/11/12 15:56, Flako wrote:
> Hello Prigge, Jim
> The printer is at 100Mb / s FULL with autonegotiation disabled, the
> desktop was as 1Gb / s FULL with autonegotiation enabled.
> The swicth A (100Mb / s) and B (1Gb / s) are connected directly to each other.
>
>
> Now connect the Desktop Printer and a switch C (only two), then swich
> C connects directly to swicth A.
> I'm sniffer on the Desktop to see differences and discard things. I
> tell them when finished.
>
> Thank you for writing so far.
> (Examples of how to find a fault will serve me now or the next)

Are your statements above accurate (printer has autonegotiation 
*DISABLED* and desktop has autonegotiation *ENABLED*)?  Both devices 
*MUST* match, even if one has autonegotiation enabled.  i.e., If the 
desktop has autonegotiation enabled, then the printer *MUST ALSO* have 
autonegotiation enabled.  Otherwise autonegotiation will fail and the 
device with autonegotiation enabled will drop down to half duplex.   See 
this:

<http://en.wikipedia.org/wiki/Duplex_mismatch#Duplex_mismatch_due_to_autonegotiation>

Hansang Bae mentioned this in a session at a prior Sharkfest during one 
of his very illuminating "Deep Dive" packet analysis sessions.

Reality Artisans, Inc.             #   Network Wrangling and Delousing
P.O. Box 565, Gracie Station       #   Apple Certified Consultant
New York, NY 10028-0019            #   Apple Consultants Network member
<http://www.realityartisans.com>    #   Apple Developer Connection member
(212) 369-4876 (Voice)             #   My PGP public key can be found at<https://keyserver.pgp.com>

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