3650 Soft Buffer and QoS Drops

[bradleyordner]

Hi, 

There is a lot of posts about the 3850 Cisco Switch and adjustment of the Softbuffer. We are seeing similar issues on the 3650 and the command is available. 

The interface is a Gigabit Interfaces and has no service-policy attached although we see the following drops for outbound - 

Drop-TH1 Drops in Queue 0

Drop-TH2  Drops in Queue 1

I would like to change the soft buffers although documentation mentions it won't do anything if no service policy applied?

Will deploying this command help in this situation?

Model - 3650-24TD & TS 

Code - 16.09.06

Thanks

[Mohsin Alam]

 Increase soft buffer value to 1200 with help of command "qos queue-softmax-multiplier 1200" 

  

This will give us the highest number of "soft buffers" the particular interface borrowed from the global pool. 

The maximum buffer a queue can use is addition of hardmax and softmax. However, the softmax value depends on how deep the buffer is utilized by other queues and interfaces. This is the Maximum threshold for the queue(100%). 

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[Leo Laohoo]

qos queue-softmax-multiplier 1200

Is this command present?

[bradleyordner]

No command is not present.

Brad

[Leo Laohoo]

Leave the system's "default" QoS alone. 

Enter the command and observe.  Re-adjust or tune the QoS only when necessary.

[bradleyordner]

Ok, will apply and see what happens. 

There is no QoS configured right now, so not sure if it will have any effect. May recommend they deploy AutoQoS if needed to activate this command?

Brad

[Joseph W. Doherty]

BTW, what you read about configuring a 3850, mostly, applies to the 3650.  (Similar situation with the 3750 and 3560.)