Re: What's wrong with autonegotiate

cbaker_at_GOODYEAR.COM
Date: 01/14/04

  • Next message: John Jolet: "Re: What's wrong with autonegotiate" 
    Date:         Wed, 14 Jan 2004 11:48:13 -0500
To: aix-l@Princeton.EDU

    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

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                          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.
    >

  • Next message: John Jolet: "Re: What's wrong with autonegotiate"

    Relevant Pages

    • Re: Whats wrong with autonegotiate
      ... I had problems with many kind of OSes, NICs, switches. ... one nic connected to one switch, then bad if you change the switch. ... I personnaly strongly advise to disable autonegotiation and setup fixed ... >ticked off our Network group and made them lock down the ports to 100/Full. ...
      (AIX-L)
    • Re: Whats wrong with autonegotiate
      ... > ports use a different negotiation method than Enterasys and other PCI NIC ... > I had problems with many kind of OSes, NICs, switches. ... > the main problem with autonegotiation is that it never doesn't work. ... > one nic connected to one switch, then bad if you change the switch. ...
      (AIX-L)
    • Re: Problems getting full duplex.
      ... Autonegotiation happens (if configured to autonegotiate ... connecting a cable (or switching on the device at the ... I know some NICs that stop the link beat if the ... system that is connected to a switch may use the best speed and duplex ...
      (comp.sys.hp.hpux)
    • Re: Frequent Netwok Up/Down link
      ... Then you might go into the switch's management console to see what it says. ... the ports that the workstations & serveruse. ... It prevents NICs ... 'flopping' between settings when they, and the switch, try to agree on the ...
      (microsoft.public.windows.server.sbs)
    • RE: W2K3R2 Cluster - 2 nodes, quad NICs, dual switches, HP Blades, bes
      ... If you are using HP c7000 chassis and you have 4 NICs in a blade, ... Cluster 1 is a file server cluster with 2 standalone servers ... The A ports are all connected to an A switch, B ports to a seperate B ...
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