Network QoS

Network QoS configuration (type network-qos) defines device-wide properties of traffic classes on NX-OS devices, such as the MTU per class, no-drop behavior and Priority Flow Control (PFC) CoS values for lossless traffic like storage or RoCE. Network class maps match CoS values, network policy maps set per-class properties, and the network QoS policy is applied system-wide as the network-qos service policy, with optional statistics collection. The global PFC watchdog settings detect and mitigate PFC storms on no-drop queues: they enable the watchdog, set its poll interval and the multipliers that control when a stuck queue is shut down and restored.

Diagram

Classes

nxos

Name	Type	Constraint	Mandatory	Default Value
devices	List	devices	No
device_groups	List	device_groups	No
global	Class	global	No
templates	List	templates	No

devices (nxos)

Name	Type	Constraint	Mandatory	Default Value
configuration	Class	configuration	No

device_groups (nxos)

Name	Type	Constraint	Mandatory	Default Value
configuration	Class	configuration	No

global (nxos)

Name	Type	Constraint	Mandatory	Default Value
configuration	Class	configuration	No

templates (nxos)

Name	Type	Constraint	Mandatory	Default Value
configuration	Class	configuration	No

configuration (nxos.devices)

Name	Type	Constraint	Mandatory	Default Value
qos	Class	qos	No

qos (nxos.devices.configuration)

Name	Type	Constraint	Mandatory	Default Value
network_class_maps	List	network_class_maps	No
network_policy_maps	List	network_policy_maps	No
system_service_policy_network	String		No
system_service_policy_network_statistics	Boolean	true, false	No
priority_flow_control	Class	priority_flow_control	No

network_class_maps (nxos.devices.configuration.qos)

Name	Type	Constraint	Mandatory	Default Value
name	String		Yes
match_type	Choice	match-any, match-all, match-first	No
match_cos_values	List	Integer[min: 0, max: 7]	No

network_policy_maps (nxos.devices.configuration.qos)

Name	Type	Constraint	Mandatory	Default Value
name	String		Yes
match_type	Choice	match-any, match-all, match-first	No
classes	List	classes	No

priority_flow_control (nxos.devices.configuration.qos)

Name	Type	Constraint	Mandatory	Default Value
watch_dog_interval	Boolean	true, false	No
watch_dog_interval_value	Integer	min: 25, max: 1000	No
watch_dog_shutdown_multiplier	Integer	min: 1, max: 40	No
watch_dog_internal_interface_multiplier	Integer	min: 0, max: 10	No
watch_dog_forced	Boolean	true, false	No
auto_restore_multiplier	Integer	min: 0, max: 100	No
fixed_restore_multiplier	Integer	min: 0, max: 400	No

classes (nxos.devices.configuration.qos.network_policy_maps)

Name	Type	Constraint	Mandatory	Default Value
name	String		Yes
mtu	Integer	min: 576, max: 9216	No
no_drop	Boolean	true, false	No
pause_pfc_cos	List	Integer[min: 0, max: 7]	No
pause_receive	Boolean	true, false	No
pause_buffer_size	Integer	min: 5000, max: 268435456	No
pause_headroom	Integer	min: 0, max: 268435456	No
pause_dynamic	Integer	min: 0, max: 255	No
pause_threshold	Integer	min: 0, max: 268435456	No
pause_resume_threshold	Integer	min: 0, max: 268435456	No
pause_resume_offset	Integer	min: 0, max: 268435456	No

Examples

Example 1: Network QoS with class maps for CoS classification, policy map with MTU and PFC pause settings

nxos:
  devices:
    - name: LEAF1
      configuration:
        qos:
          network_class_maps:
            - name: c-nq-voice
              match_type: match-any
              match_cos_values:
                - 4
                - 5
            - name: c-nq-storage
              match_type: match-any
              match_cos_values:
                - 3
          network_policy_maps:
            - name: p-nq-fabric
              match_type: match-first
              classes:
                - name: c-nq-voice
                  mtu: 1500
                - name: c-nq-storage
                  mtu: 9216
                  no_drop: true
                  pause_pfc_cos:
                    - 3
          system_service_policy_network: p-nq-fabric
          system_service_policy_network_statistics: true

Example 2: Global PFC watchdog with tuned poll interval and restore multipliers

nxos:
  devices:
    - name: LEAF1
      configuration:
        qos:
          priority_flow_control:
            watch_dog_interval: true
            watch_dog_interval_value: 200
            watch_dog_shutdown_multiplier: 5
            auto_restore_multiplier: 20
            fixed_restore_multiplier: 50