Getting the below commit error when setting up a new forwarding class:

user@host# set class-of-service interfaces et-* unit * forwarding-class FC_BEST-EFFORT 

user@host# set class-of-service interfaces xe-* unit * forwarding-class FC_BEST-EFFORT 

user@host# set class-of-service interfaces ge-* unit * forwarding-class FC_BEST-EFFORT 

user@host# set class-of-service interfaces ae* unit * forwarding-class FC_BEST-EFFORT 

user@host# set class-of-service forwarding-classes class FC_BEST-EFFORT queue-num 0 

user@host# set class-of-service forwarding-classes class FC_BEST-EFFORT priority low 

user@host# commit check 

[edit class-of-service forwarding-classes]

'class'

'queue' and 'class' cannot coexist

error: configuration check-out failed: (statements constraint check failed)

Setting up a new forwarding class and assigning a queue number under the set class-of-service forwarding-classes class hierarchy, while also having other forwarding classes assigned to queues under the set class-of-service forwarding-classes queue hierarchy

Both "queue" and "class" cannot coexist, we have 2 options:

1- set the queue-num statement under the class hierarchy, this allows you to configure up to 16 forwarding classes with multiple forwarding classes mapped to single queue:

example:

set class-of-service forwarding-classes class Class_name queue-num 0

2- set the queue statement allows you to configure up to eight forwarding classes with one-to-one mapping to output queues:

example

set class-of-service forwarding-classes queue 0 Class_name

It all depends on the type of queue mapping we need.