Catalyst Qos Class class-default BEWARE

Hi Guys,

Was reading one of Cisco's new Medianet design guides yesterday and came across this little Gotcha.

Note: While the Catalyst 3750-E MQC syntax includes an implicit class-default, any policy actions assigned to this class are not enforced. Therefore, an explicit class DEFAULT is configured to enforce a marking/remarking policy to DSCP 0 for all other IP traffic.

Whislt they refer to the 3750-E above they use this as a generic term to cover the Cisco 2960, 2975, 3560/3570E and G models families

As an example, we are now going to need something similiar to the below which I have had to drop onto my Customer's Switches.


ip access-list extended DEFAULT
 remark EXPLICIT CLASS-DEFAULT
 permit ip any any
!
class-map match-all DEFAULT
 match access-group DEFAULT
!
policy-map IPPHONE+PC
 class VVLAN-VOICE
  set ip dscp ef
  police 128k 8000 exceed-action drop
 class VVLAN-CALL-SIGNALING
  set ip dscp cs3
  police 32k 8000 exceed-action drop
 class VVLAN-ANY
  set ip dscp default
  police 32k 8000 exceed-action policed-dscp-transmit
 class DEFAULT
  set ip dscp default
  police 10m 8000 exceed-action policed-dscp-transmit
!

Look at the "Note" section at the bottom of the config section of the following URL for confirmation of the above;
http://www.cisco.com/en/US/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND_40/QoSCampus_40.html#wp1098677


Cheers,

Steve

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