1. This forum section is a read-only archive which contains old newsgroup posts. If you wish to post a query, please do so in one of our main forum sections (here). This way you will get a faster, better response from the members on Motherboard Point.

Sunfire v240 and v480 speed negotiation

Discussion in 'Sun Hardware' started by Andrew, Nov 13, 2003.

  1. Andrew

    Andrew Guest

    At my facility we had been in the habit of hard coding the ports
    on the network devices to full duplex to keep the Sun machines
    happy. I observed that when we plugged the on-board 1000/100/10
    ports of the 240's and 480's into catalyst 10/100 ports that had
    been hard-coded to full-duplex, that the ports on the Suns come
    up half-duplex. When we set the network side to autonegotiate, both
    both sides happily come up at 100/full-duplex.
     
    Andrew, Nov 13, 2003
    #1
    1. Advertisements

  2. Andrew

    Chris Morgan Guest

    I've found a case where a blade 1000 didn't succesfully auto-negotiate
    full duplex, and I too hard-code the settings now just out of
    necessity.

    However, the v240 and v480 have different NIC hardware and it seems
    wise to default back to the normal advice which is to allow
    auto-negotiation wherever possible, until that's proven to fail.

    Chris
    --
    Chris Morgan
    "Post posting of policy changes by the boss will result in
    real rule revisions that are irreversible"

    - anonymous correspondent
     
    Chris Morgan, Nov 13, 2003
    #2
    1. Advertisements

  3. Andrew

    Adam Rheaume Guest

    We had this same issue with the V210 and where told by sun that Auto
    Negotiation was recommended on the CE interfaces.

    -=>Adam<=-
     
    Adam Rheaume, Nov 13, 2003
    #3
  4. Andrew

    Rick Jones Guest

    At my facility we had been in the habit of hard coding the ports on
    Right - when you hardcode one side, that causes autoneg to "fail" and
    the spec says that if autoneg fails, the device doing the autoneg
    _must_ go into half-duplex operation. So, when/if the system is set
    to auto, and the switch to full, you get a duplex mismatch.
    Indeed.

    rick jones

    How Autoneg is supposed to work:

    When both sides of the link are set to autoneg, they will "negotiate"
    the duplex setting and select full duplex if both sides can do
    full-duplex.

    If one side is hardcoded and thus not using autoneg, the autoneg
    process will "fail" and the side trying to autoneg is required by spec
    to use half-duplex mode.

    If one side is using half-duplex, and the other is using full-duplex,
    sorrow and woe is the usual result.

    So, the following table shows what will happen given various settings
    on each side:

    Auto Half Full

    Auto Happiness Lucky Sorrow

    Half Lucky Happiness Sorrow

    Full Sorrow Sorrow Happiness

    Happiness means that there is a good shot of everything going
    well. Lucky means that things will likely go well, but not because you
    did anything correctly :) Sorrow means that there _will_ be a duplex
    mis-match.

    On the side running half-uplex you will see various errors and
    probably a number of late collisions. On the side running full-duplex
    you will see things like FCS errors.
     
    Rick Jones, Nov 13, 2003
    #4
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.