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Without 'MLS QOS' in 6500 does any interface queueing and trusting take place?

I have a 6500 that does not have 'mls qos' global configured, although the interfaces do have 'mls qos trust dscp' on them as in:

interface GigabitEthernet3/3

switchport

switchport access vlan 536

switchport mode access

switchport voice vlan 910

logging event link-status

mls qos trust dscp

spanning-tree portfast

When I 'show queueing int gx/x', it does show the default queueing structure of the interface as in:

LLT-6509AS-A#sh queueing int g3/3
Interface GigabitEthernet3/3 queueing strategy:  Weighted Round-Robin

  QoS is disabled globally
  Port is untrusted
  Extend trust state: not trusted [COS = 0]
  Default COS is 0
    Queueing Mode In Tx direction: mode-cos
    Transmit queues [type = 1p3q8t]:
    Queue Id    Scheduling  Num of thresholds
    -----------------------------------------
       01         WRR                 08
       02         WRR                 08
       03         WRR                 08
       04         Priority              01

---- snip ----

    queue thresh cos-map
    ---------------------------------------
    1     1      0 1 2 3 4 5 6 7
    1     2     
    1     3     
    1     4     
    1     5     
    1     6     
    1     7     
    1     8     


  Packets dropped on Transmit:
    BPDU packets:  0

    queue              dropped  [cos-map]
    ---------------------------------------------
    1                        0  [0 1 2 3 4 5 6 7 ]
    2                        0  []
    3                        0  []
    4                        0  []

  Packets dropped on Receive:
    BPDU packets:  0

    queue              dropped  [cos-map]
    ---------------------------------------------
    1                        0  [0 1 2 3 4 5 6 7 ]

So just what does the global 'mls qos' do?  Without it is the command 'mls qos trust dscp' ignored?

I'm trying to track down where in our network dscp settings are being stripped out of packets and this is when I noticed the 'mls qos' was not configured.

1 REPLY
Hall of Fame Super Silver

Re: Without 'MLS QOS' in 6500 does any interface queueing and tr

it enables QOS on the switch, without it no QOS is being used.

Sent from Cisco Technical Support iPhone App

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