Showing results for 
Search instead for 
Did you mean: 

QoS Class Default

Level 1
Level 1

I am trying to set up QoS specifically CBWFQ.  My question is "is it correct if the traffic doesn't match any Queues traffic will be placed in Class-default?"

I guess this is like the permit ip any any at the end of an access-list.  I don't want the traffic to not match a queue and be dropped because of it.  Would the following config work?

class-map match-all sttx

  match vlan 543

policy-map policy1

  class sttx

    bandwidth 100000   <-- Hundred megabytes

int fa1/0

service-policy output policy1

2 Replies 2

John Blakley
VIP Alumni
VIP Alumni

Correct. You won't drop any traffic, but whatever doesn't match in any class does fall under the class-default. Your current config guarantees 100Mb of bandwidth to vlan 543, but if vlan 12 were to come in it doesn't guarantee anything for 12 and will just match on the class-default.


*** Please rate all useful posts ***

HTH, John *** Please rate all useful posts ***

Joseph W. Doherty
Hall of Fame
Hall of Fame


The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.

Liability Disclaimer

In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.


Yes, any unmatched traffic goes to the class-default class.  This class is always present, even when not explicitly defined.