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overscriptions of 32 ports blades ?

jjpeyrache
Level 1
Level 1

hello

are they anyway to see that 32ports

has been or is overloaded ?

are they any counters or events that display that ?

thanks in advance

JYP

4 Replies 4

tblancha
Cisco Employee
Cisco Employee

No, there is no way to see if you have encountered oversubscription.

any way to see dropped packets counters on ports ?

strange ??

JYP

To get the stats for interface 1/1 you would do:

show interface fc1/1

or

show interface fc1/1 details

or

show interface fc1/1 counters

Also, a crude way to see if you're hitting the bandwidth ceiling on an oversubscribed card would be:

show interface fc1/1 - 4 counters brief

This will give you the average (5 minute avg) input and output rates for ports 1 through 4. If you total those up and it's at 2.5 Gbps, then you're at the ceiling for that forwarding ASIC (4-port group). I'd have to double-check the 2.5Gbps figure, but that's the number I'm recalling at the moment. You could also do this in the GUI, but I don't know much about that. If you wanted to see historical throughput for those ports, you would have to have a Fabric Manager server installed. With the free version you can't get historical throughput data....I'm pretty sure.

Hope that helps.

Josh

Also, I should elaborate on the oversubscription characteristics of those blades. The reason I used a range of 4 ports in the example I gave is that the oversubscription rate is 3.2:1 at the forwarding ASIC level. 4 ports share an ASIC, which has (I believe around 2.5Gbps bandwidth). Each of the 4 ports is capable of using its full 2Gbps rate if it is not competing with the other 3 ports on that ASIC.

This is why you should do all of your ISLs on the 16-port cards. They require full line rate, so if you put an ISL on a 32-port card, you must use the 1st port in the 4-port group and the other 3 ports will be shut down and not usable. It defeats the purpose of buying a 32-port card. That card is purposely oversubscribed so you get high port-count when you know your hosts will never need the full 2Gbps pipe (most Windows hosts).

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