Re: Alternatives to storm-control on Cat 6509.

From: Mike Bartz (no email)
Date: Tue Aug 25 2009 - 16:21:42 EDT

  • Next message: Bill Stewart: "Re: FCCs RFC for the Definition of Broadband"

    On Mon, Aug 24, 2009 at 4:59 PM, Nick Hilliard <> wrote:

    > On 24/08/2009 19:03, Holmes,David A wrote:
    >> Additionally, and perhaps most significantly for deterministic network
    >> design, the copper cards share input hardware buffers for every 8 ports.
    >> Running one port of the 8 at wire speed will cause input drops on the
    >> other 7 ports. Also, the cards connect to the older 32 Gbps shared bus.
    > IMO, a more serious problem with the 6148tx and 6548tx cards is the
    > internal architecture, which is effectively six internal managed gigabit
    > ethernet hubs (i.e. shared bus) with a 1M buffer per hub, and each hub
    > connected with a single 1G uplink to a 32 gig backplane. Ref:
    > In Cisco's own words: "These line cards are oversubscription cards that are
    > designed to extend gigabit to the desktop and might not be ideal for server
    > farm connectivity". In other words, these cards are fine in their place,
    > but they are not designed or suitable for data centre usage.
    > I don't want to sound like I'm damning this card beyond redemption - it has
    > a useful place in this world - but at the expense of reliability,
    > manageability and configuration control, you will get useful features
    > (including broadcast/unicast flood control) and in many situations very
    > significantly better performance from a recent SRW 48-port linksys gig
    > switch than from one of these cards.
    > Nick
    We experienced the joy of using the X6148 cards with a SAN/ESX cluster.
    Lots of performance issues! A fairly inexpensive solution was to switch to
    the X6148A card instead, which does not suffer the the 8:1
    oversubscription. It also supports MTU's larger than 1500, which was
    another shortcoming of the older card.


    Mike Bartz

  • Next message: Bill Stewart: "Re: FCCs RFC for the Definition of Broadband"

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