Re: What's wrong with autonegotiate

From: John Jolet (john.jolet@FXFN.COM)
Date: Wed Jan 14 2004 - 12:07:38 EST


cabletron switch sucked when i used it several years ago, but then
again, it also seemed to have trouble talking blade-to-blade across it's
own backplane, too (shrug) seems you'd kinda want that to work before
you start shipping the product.

On Wed, 2004-01-14 at 10:48, cbaker@GOODYEAR.COM wrote:
> Folks,
>
> Thanks for the overwhelming reply to this question.
>
> Could the issue be that Cisco is not talking the "preferred" way? Seems to
> be a common thread in most of the replies. I believe Cisco 10/100BaseT
> ports use a different negotiation method than Enterasys and other PCI NIC
> cards (NWAY, I think).
>
> Also, I am speaking of workstations, desktops, PC's, printers, etc. - Not
> necessarily servers.
>
> Does anyone have experience on non-Cisco equipment?
>
> Christopher M. Baker
> Senior Technical Support Analyst
> DSE/TCO
> Goodyear Tire and Rubber Company
>
> =================================================
> Contains Confidential and/or Proprietary Information.
> May not be copied or disseminated without the expressed
> written consent of The Goodyear Tire & Rubber Company.
> =================================================
>
>
>
>
> Thierry ITTY
> <thierry.itty@BE To: aix-l@Princeton.EDU
> SANCON.ORG> cc: (bcc: Chris Baker/NA/GDYR)
> Sent by: IBM AIX Subject: Re: What's wrong with autonegotiate
> Discussion List
> <aix-l@Princeton
> .EDU>
>
>
> 01/14/2004 04:18
> AM
> Please respond
> to IBM AIX
> Discussion List
>
>
>
>
>
>
> I consider that a autonegotiated connexion that works fine is just a matter
> of luck
>
> I had problems with many kind of OSes, NICs, switches.
>
> the main problem with autonegotiation is that it never doesn't work. it
> always works, but only at some percentage of the nominal throughput,
> depending on the traffic profile. it may work fast in one way but very slow
> in the other (ie upload vs download) or it may be fast with one protocol
> and slow with another (ie telnet vs ftp). and so on. it may be fine with
> one nic connected to one switch, then bad if you change the switch.
>
> I personnaly strongly advise to disable autonegotiation and setup fixed
> duplexity and speed on all nics and all switch ports
>
>
>
> A 15:17 13/01/2004 -0500, vous avez écrit :
> >I have noticed lately that some still say in this site "DO NOT
> >AUTONEGOTIATE your speed/duplex on IBM AIX boxes.
> >
> >We had major problems with that back in the early AIX 433 (or earlier)
> days
> >and back with the 43P-140 [7043-140] (and first cut of the 150's and
> 260's)
> >and the first auto-negotiating ethernet cards.
> >
> >BUT, we were told that with the newer boxes (about the time when they went
> >from beige to black cases) that the problem was fixed. It was NOT an OS
> >issue but rather a NIC issue.
> >
> >In our case, we had (and still have) a lot of EnteraSys (Cabletron)
> >switches. We were told that the "world" used one negotiation schema (i.e.
> >Cabletron, HP, SUN, SGI), but IBM was using a different method in those
> >ethernet cards. So, we saw that the NIC and the network hub/port were
> >never coming to an agreement at what speed and duplex to use. So, we
> >ticked off our Network group and made them lock down the ports to
> 100/Full.
> >
> >But, since then, (a couple years now at least) we have been setting both
> >the NIC and the network port to autonegotiate and have had no problems.
> >



This archive was generated by hypermail 2.1.7 : Wed Apr 09 2008 - 22:17:30 EDT