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.

Regards.

Comments

  • 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
    target.

    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.

    http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/qos/Cisco_Nexus_5000_Series_NX-OS_Quality_of_Service_Configuration_Guide_chapter3.html#con_1120879

    Vikram

    CCIE#22735

     

     

  • 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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