%CDP-4-DUPLEX_MISMATCH: duplex mismatch between 6506 & WS-CBS3110G-S-I which is a Cisco switch for IBM blade H

Unanswered Question
May 26th, 2010
User Badges:

cat6500 side is fastethernet and set to speed 100 and duplex full

ibm side is gig is set to auto/ auto

Things working fine with the error above

But when i set the ibm side to speed 100 and duplex full or half ports will show down/down

i have total of 4 ports on each side forming etherchannel using desirable mode non-silent on the 6500 and same mode on ibm side but without the non-silent command

Any help greatly appreciated.


  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Giuseppe Larosa Wed, 05/26/2010 - 11:31
User Badges:
  • Super Silver, 17500 points or more
  • Hall of Fame,

    Founding Member

Hello Mohammed,

you should use autonegotiation on both sides and all member links have to be configured on the same way both sides.

Hope to help


mhasabal Wed, 05/26/2010 - 12:09
User Badges:

thanks Giuseppe

i was just trying to avoid the auto

glen.grant Wed, 05/26/2010 - 12:16
User Badges:
  • Purple, 4500 points or more

   My guess is you have the wrong cable between them and auto mdix is correcting the pins.  Auto mdix only works when set to auto/auto, when you try to hardcode the ports to a speed it will bring the link down .


This Discussion