Applying CoS Queue Mapping based on Re-Marked DSCP in vFlow

NetVisor OS allows a vFlow policy to mark or re-mark matched outgoing packets with a DSCP value. For this purpose, it supports the set-dscp action-value parameter.

For example, a vFlow policy called myflow can be modified to remark to DSCP 46 any matching traffic like so: 

CLI (network-admin@switch) > vflow-modify name myflow action set-dscp action-value 46

In this case, NetVisor OS does not modify the egress port queue selection for outgoing traffic.

As discussed above, NetVisor OS also allows you to create named DSCP maps as independent objects, and to apply the maps to ingress ports for classification of packets based on the DSCP markings.

In addition to that, you can apply the same DSCP maps in vFlow policies by using the dscp-map map-name parameter.

Note: Before you can apply a DSCP map, you should verify that it’s already created with the appropriate name. Once the map is used in a vFlow policy, it cannot be deleted until it remains in use.

By using the DSCP maps in vFlow policies, NetVisor OS can modify the egress port queue selection for outgoing traffic based on the DSCP-to-CoS associations configured by the network administrator.

You can specify the name of a DSCP map in the vflow-create command:

dscp-map dscp-map name | none

Specify the DSCP map to apply on the flow.  

Please reapply if map priorities are updated.

For example, you can modify the aforementioned vFlow policy called myflow to affect egress queue selection by applying a (default) DSCP map like so:

CLI (network-admin@switch) > dscp-map-create name dscp-map1 scope fabric

CLI (network-admin@switch) > dscp-map-pri-map-show name dscp-map1

name      pri dsmap

--------- --- -----------

dscp-map1 0   none

dscp-map1 1   8,10,12,14

dscp-map1 2   16,18,20,22

dscp-map1 3   24,26,28,30

dscp-map1 4   32,34,36,38

dscp-map1 5   40

dscp-map1 6   48

dscp-map1 7   56

CLI (network-admin@switch) > vflow-modify name myflow dscp-map dscp-map1

CLI (network-admin@switch) > vflow-show name myflow format name,dscp-map,precedence,action,action-value,enable,table-name

name   dscp-map  precedence action   action-value enable table-name           

------ --------- ---------- -------- ------------ ------ -------------------- 

myflow dscp-map1 default    set-dscp 32           enable System-L1-L4-Tun-1-0