Jon Marshall Fri, 09/18/2009 - 10:13


The WS-X6548 has 6 port groups and each groups shares a single ASIC. Each ASIC has a 1Gbps connection to the switch fabric.

So there is a large amount of oversubscription. These cards are really for end devices ie. the wiring closet and should not be used for servers etc.


pndennie93 Fri, 09/18/2009 - 10:32

So does the 6700's share this same issue? And we are also migrating to the Nexus 7K' can I expect the same over-subscriptions?

pndennie93 Fri, 09/18/2009 - 10:34

also are there any IOS commands that can help me determine is the ASIC is over-subscribed

Jon Marshall Fri, 09/18/2009 - 10:44

No the 67xx modules generally don't share this issue. The 6748-GE-TX for example has 2 x 20Gbps connection to the switch fabric. With 48 x 10/100/1000 ports if you had 48 servers all generating 1Gbps of traffic each that would oversubscribe the card ie. 48Gbps from servers but only 40Gbps to switch fabric, but that is unlikely to happen.

For server farms etc. the 6748 is a much better choice. Be aware that with the 67xx modules you have to use the Sup720.

Not used the Nexus switches.


pndennie93 Fri, 09/18/2009 - 10:47

Have the SUP 720's. The reason I am bringing this up is I have some over runs on a port channel and they are on ports 6 and 8 in the same blade and another port channel is on 2 and 4. I think I am killing the ASIC but would like proof....


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