I'm testing some Cisco 3650 switches with Cisco VoIP handsets and using auto qos. Is there a way to see if qos is kicking in and prioritising the voice traffic? Tried looking through the cli and can't find anything.

Thanks for reading, appreciate any advice.

2 Answers 2


Probably you are looking for things like:

show mls qos
show mls qos interface
show mls qos interface <slot/port> stat
show mls qos interface buffers
show mls qos interface queuing
show mls qos queue-set
show policy-map interface


Depending on your IOS version, you may need to use these commands:

show policy-map <policy map>
show qos interface <slot/port>
show interface <slot/port> counters detail
show interface <slot/port> counters all
  • Thanks for the response, those commands aren't supported on the 3650, I found a few of these online and expected these might be for a different model. If I do these on another switch where their supported any idea what I'd be looking for?
    – calabi
    Commented Apr 18, 2017 at 18:42
  • Those commands are what we use on the Cisco 3650. What IOS version are you using?
    – Ron Maupin
    Commented Apr 18, 2017 at 18:43
  • IOS XE I believe
    – calabi
    Commented Apr 18, 2017 at 18:45
  • Do a show version command to let us know what IOS version you are using.
    – Ron Maupin
    Commented Apr 18, 2017 at 18:46

Aside from CLI show commands, you may want to look into 3rd party software with traffic visibility. I cannot give specific names as applications and vendor recommendations are off-topic.

However, there are a lot of options out there that give granular visibility of the traffic flows and break them down and track traffic tags such as IP ToS. Look for applications with NetFlow support.

Cisco basic NetFlow v5 will track the following information:

  • Ingress interface (SNMP ifIndex)
  • Source IP address
  • Destination IP address
  • IP protocol Source port for UDP or TCP, 0 for other protocols
  • Destination port for UDP or TCP, type and code for ICMP, or 0 for other protocols
  • IP Type of Service

While you may not be able to tell whether queues are explicitly being congested from the reports, you are often able to tell whether tags are being properly applied and honored.


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