[c-nsp] QOS Tx Drops on N3k

[Sergey S.]

Hi, Saku!

There is only one more 10G port (ingress) in the same VLAN.



On 03/18/2018 11:47 AM, Saku Ytti wrote:
> Hey Sergey,
>
>
> Your intuition seems right. My initial guess as well would be that
> these are consequence of microbursts. So any effort to understand
> buffer utilisation is needed to exclude or prove that.
>
>
> Do you have ingress ports operating at 100GE or do you have multiple
> 10GE ingress ports competing for that 10GE egress port?
>
>
> On 18 March 2018 at 00:52, Sergey S. <gforgx at fotontel.ru> wrote:
>> Hi,
>>
>> I'm running NXOS 7.0(3)I5(2) on N3K-C3064PQ-10GE.
>>
>> Output discards counter is gradually incrementing on one 10G port despite it
>> not being oversubscribed in those moments of time.
>>
>> If I look at "sh hardware internal interface asic counters module 1" these
>> drops are displayed as QOS Tx Drops.
>>
>> I've tried setting up "hardware profile buffer info port-threshold" even to
>> the lowest values (e. g., 1%) to figure out if there is a problem with QoS
>> queues, however there isn't any information in "sh hardware internal buffer
>> info pkt-stats port-log" (most likely I don't understand the concept of
>> buffer monitoring and/or it's totally unrelated to my issue).
>>
>> There isn't any special QoS configuration on the switch. It is just as
>> follows:
>>
>> policy-map type network-qos jumbo
>>    class type network-qos class-default
>>      mtu 9216
>> system qos
>>    service-policy type network-qos jumbo
>>
>> Not sure whether this gives some clue, anyway, the port in the subject is
>> connected to a large broadcast domain (Internet Exchange Point).
>>
>> Thank you for any hint!
>>
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>
>