QOS configuration on Cisco Nexus 5000

Hi all


Can somebody knows about difference between network-qos class maps and simple qos class maps type.

I have a problem with a basic cos/precedence remarking, it seems that Cos can only be configured with network-qos class-maps/policy-maps types.

By the way if somebody has already test to match a cos field and remark it to precedence, thanks for help.



  • Hello Kurt,


      The qos class-maps and the network-qos class maps, are referenced by their corresponding Policy maps of the same type. The difference is that the qos policy maps sets the qos-group corresponding to the system class. It can be applied either system wide or on interface and ONLY applies to the input traffic.

    The network-qos, on the other hand , can do a lot of other things. The complete list is there in the cisco doc mentioned below but yes, for remarking , we need to use this policy map of type network qos. The other difference is network-qos network-qos policy can only be attached to the system qos

    So, the answer is that is you are looking ONLY for remarking then, you will have to use the network-qos type since the other two types ( queuing and qos) will not do it. See the below link for a complete understanding.






  • Simple QOS class-maps attached to policy maps are used for traffic classification mainly.

    Typically you classify traffic and put it to some placeholder ( qos-group). This can be done only on ingress traffic.

    Network QoS policy maps are used for traffic marking, MTU set, drop/no-drop policy,etc.

    You refer in class-map to particular qos-group ( that you used in simple qos class-map) and make action in policy-map


    for sample

    you have ACL TEST that matches some traffic


    class-map type qos match-any TEST-CLASS

    match access-group name TEST


    Policy-map type qos 

    class TEST-CLASS

    set qos-group 2 ( put placeholder here)


    And later in Network QoS class map you refer to previously classified traffic

    class-map type network-qos match-any MY-CLASS

    match qos-group 2 ( refer to previously classified traffic)


    Policy-map type network-qos

    class MY-CLASS

    set mtu XXXX ( change MTU for example)


    Don't forget to attach policy-maps either system wide ( under system qos).

    Simple Qos Policy maps can also be applied to interface. Network-Qos maps goes under system qos only.



    There is also third type class-maps/policy maps - QUEUEING .

    It is being used for bandwidth allocation, priority queueing, WRR

    This can be attached on ingress/egress  interface, as well as system wide



    hope that helps




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