Managing Traffic Classes with vFlow


Netvisor One provides a full set of traffic class features, including the ability to view and create traffic classes, as well as assign traffic classes to flows to manage the quality of service of the flow traffic and shape the traffic passing through an Netvisor One fabric.


To display the currently defined traffic classes:


CLI (network-admin@Leaf1) >  vflow-class-show


name          scope  type   priority

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

meter         fabric system 0        

guaranteed_bw fabric system 9        

lossless      fabric system 10       

control       fabric system 11

 

The higher the priority number, the higher the priority of the class. To add a vflow class, use the vflow-class-create command:


CLI (network-admin@Leaf1) >  vflow-class-create name traffic-1 scope fabric priority 5


This creates a traffic class with a scope of fabric and medium priority.


To add a traffic class to a vFlow, create a vFlow and assign a traffic class. In this case the flow is for a single IP address:


CLI (network-admin@Leaf1) >  vflow-create name losslessflow scope local src-ip 10.11.1.10 src-ip-mask 255.255.255.255 action none flow-class lossless


CLI (network-admin@Leaf1) >  vflow-show name losslessflow layout vertical


switch: aquila12

name: losslessflow

scope: local

type: vflow

vlan: 0

:

in-port:

out-port:

ether-type: 0

src-ip: 10.11.1.10

dst-ip:::

src-port: 0

dst-port: 0

proto: ip

flow-class: lossless

bw-max: 0

pri: 0

action: none

action-value: 0

transient: no

 

Traffic from IP address 10.11.1.10 now has a very high priority throughout the switch. For a similar high priority throughout the fabric use scope fabric rather than scope local.


When a TCP session goes through the NPU, and capacity is exceeded, the return traffic with TCP ACK packets can get dropped from the session. To avoid this, create a flow that matches the TCP ACK packets and set a higher precedence for it.