Ports on ASIC

Hey All,

 

Having an issue at work with output drops on ports with high traffic flow, using 6513 and 6548 line cards, I know that the port to ASIC grouping isnt great on these so we are having to spead Ether channels accross differnt ASIC's to avoid output drops.

 

In an ideal world without budgets we would upgrade to Nexus, but we have a 6509-E chassis and I was thinking if we got a Sup 2T for it and some 6700 line cards would this help our issue, does that give 1GB per port with no over subscription, I have read some Cisco docs and cant get a clear answer, So wounder if anyone in here have any thoughts ?

 

Ricky

Comments

  • Yes it will work as you wish. I would also work towards a VSS if you
    can spend the money.

    Nexus and 6500 are very different products when it boils down to
    campus core x datacenter core. You should pick 6500 for campus core
    and leave nexus only for datacenter very high throughput scenarios.

    The corner cases where Nexus doesn't work like Catalyst (orphan ports
    etc) make the Nexus a bit limited related to a 6500 VSS. On the other
    hand, if you have a full chassis redundant solution (including
    servers) without orphan ports cases, you should go for Nexus.

    2014-02-20 10:07 GMT-03:00 RickyHines :
    > Hey All,
    >
    >
    >
    > Having an issue at work with output drops on ports with high traffic flow,
    > using 6513 and 6548 line cards, I know that the port to ASIC grouping isnt
    > great on these so we are having to spead Ether channels accross differnt
    > ASIC's to avoid output drops.
    >
    >
    >
    > In an ideal world without budgets we would upgrade to Nexus, but we have a
    > 6509-E chassis and I was thinking if we got a Sup 2T for it and some 6700
    > line cards would this help our issue, does that give 1GB per port with no
    > over subscription, I have read some Cisco docs and cant get a clear answer,
    > So wounder if anyone in here have any thoughts ?
    >
    >
    >
    > Ricky
    >
    >
    >
    >
    > INE - The Industry Leader in CCIE Preparation
    > http://www.INE.com
    >
    > Subscription information may be found at:
    > http://www.ieoc.com/forums/ForumSubscriptions.aspx
  • Thanks for the reply, obviously id love to put in Nexus as its for a server farm enviroment but budgets are tight so having to use what we have.

     

    I think this way will give better port utilization but obviously as we have a 48 port card and the back plane is 40GB per line card there has to be some slight over subscriptin per port.

  • peetypeety ✭✭✭

    You can put up to 5 6700-series line cards in the bottom of your existing 6513, as long as you have a high-speed fan tray, 2500W or bigger power supplies (you probably have this already given that it's a 6513), and a Sup720.  The 6700 series cards are slightly oversubscribed, so I'd encourage you to put descriptions on ports 11/12/23/24/35/36/47/48 that say "Do Not Use - Reserved for Oversubscription".

    I think you can also put the 6724 SFP card in slots 1-8 of a 6513, as it only uses one 20G fabric connection and that's all you have on those slots.

    Personally, I'd stay away from VSS.  I saw it as useful in two applications: increased 10G density for times when the (logical) box count is crucial to the topology, and L3 redundancy at the L3/L2 perimeter.  However, you put all of your eggs in one basket-shaped control plane, and need to be a VSS ninja to do upgrades smoothly.  VPC on Nexus means you can glue two boxes togehter without combining the control plane, and (assuming N7K with dual sups) you get true seamless upgrades (unless you need to update the EPLD on the linecards, in which case it can get a little messy). 

    If you're looking for ten-gig, stay miles away from the 6704, even
    though the 6708 is 100% oversubscribed and the 6716 is 300%
    oversubscribed, as they have far more packet buffer than the 6704.

  • Thanks for the input I appreciate it, some good advice there definatly lots of options to think about.

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