Contents

PFC commands· 1

display priority-flow-control 1

priority-flow-control (Ethernet interface view) 2

priority-flow-control (system view) 3

priority-flow-control no-drop dot1p (Ethernet interface view) 4

priority-flow-control no-drop dot1p (system view) 5

 

 

PFC commands

display priority-flow-control

Use display priority-flow-control to display the PFC information for an interface.

Syntax

display priority-flow-control interface [ interface-type [ interface-number ] ]

Views

Any view

Predefined user roles

network-admin

network-operator

Parameters

interface-type: Specifies an interface type. If you do not specify an interface type, the command displays the PFC information for all Ethernet interfaces.

interface-number: Specifies an interface number. If you do not specify an interface number, the command displays the PFC information for all Ethernet interfaces of the specified type.

Examples

# Display the PFC information for all Ethernet interfaces.

<Sysname> display priority-flow-control interface

Conf -- Configured mode   Ne -- Negotiated mode   P -- Priority

Interface     Conf Ne  Dot1pList   P Recv       Sent

GE1/0/1       Auto On  0,2-3,5-6   0 178        43

Table 1  Command output

Field	Description
Conf -- Configured mode	Locally configured PFC status.
Ne -- Negotiated mode	Negotiated PFC status.
P -- Priority	802.1p priority value for which PFC is enabled.
Interface	Abbreviated name of the interface.
Conf	Locally configured PFC status: ·     Auto—The interface is configured to autonegotiate the PFC status with the remote end. ·     Off—PFC is disabled for the interface. ·     On—PFC is enabled for the interface.
Ne	Negotiated PFC status: ·     Off—PFC is disabled. ·     On—PFC is enabled.
Dot1pList	802.1p priorities that are enabled with PFC. 802.1p priority values 0 through 7 are available.
P	An 802.1p priority is displayed only when the 802.1p priority is enabled with PFC and the interface has received or sent packets with the 802.1p priority. In the current software version, only 0 can be displayed.
Recv	Number of received PFC pause frames.
Sent	Number of sent PFC pause frames.

‌

Related commands

priority-flow-control

priority-flow-control no-drop dot1p

priority-flow-control (Ethernet interface view)

Use priority-flow-control to enable PFC on an Ethernet interface.

Use undo priority-flow-control to disable PFC.

Syntax

priority-flow-control { auto | enable }

undo priority-flow-control

Default

PFC is disabled on Ethernet interfaces.

Views

Ethernet interface view

Predefined user roles

network-admin

Parameters

auto: Specifies PFC in auto mode. In this mode, the local end automatically negotiates the PFC status with the remote end.

enable: Forcibly enables PFC.

Usage guidelines

The local device notifies the remote end to stop sending packets carrying the specified 802.1p priority if all of the following conditions exist:

·     Both the local end and the remote end have PFC enabled.

·     Both the local end and the remote end have the priority-flow-control no-drop dot1p dot1p-list command configured.

·     The specified 802.1p priority is in the 802.1p priority list specified by the dot1p-list argument.

·     The local end receives packets carrying the specified 802.1p priority, and the received packets cause congestion.

When congestion is eliminated, the local end notifies the remote end to continue to send packets carrying the specified 802.1p priority. In this way, the local device can forward packets carrying 802.1p priorities in the specified 802.1p priority list without packet drops.

If you execute this command in system view and Ethernet interface view multiple times, the most recent configuration takes effect.

Examples

# Enable PFC on GigabitEthernet 1/0/1.

<Sysname> system-view

[Sysname] interface gigabitethernet 1/0/1

[Sysname-GigabitEthernet1/0/1] priority-flow-control enable

Related commands

display priority-flow-control

priority-flow-control (system view)

priority-flow-control no-drop dot1p

priority-flow-control (system view)

Use priority-flow-control to enable PFC on all Ethernet interfaces.

Use undo priority-flow-control to disable PFC on all Ethernet interfaces.

Syntax

priority-flow-control { auto | enable }

undo priority-flow-control

Default

PFC is disabled on Ethernet interfaces.

Views

System view

Predefined user roles

network-admin

Parameters

auto: Specifies PFC in auto mode. In this mode, the local end automatically negotiates the PFC status with the remote end.

enable: Forcibly enables PFC.

Usage guidelines

The local device notifies the remote end to stop sending packets carrying the specified 802.1p priority if all of the following conditions exist:

·     Both the local end and the remote end have PFC enabled.

·     Both the local end and the remote end have the priority-flow-control no-drop dot1p command configured.

·     The specified 802.1p priority is in the 802.1p priority list specified by the dot1p-list argument.

·     The local end receives packets carrying the specified 802.1p priority, and the received packets cause congestion.

When congestion is eliminated, the local end notifies the remote end to continue to send packets carrying the specified 802.1p priority. In this way, the local device can forward packets carrying 802.1p priorities in the specified 802.1p priority list without packet drops.

If you execute this command in system view and Ethernet interface view multiple times, the most recent configuration takes effect.

Examples

# Enable PFC on all Ethernet interfaces.

<Sysname> system-view

[Sysname] priority-flow-control enable

Related commands

display priority-flow-control

priority-flow-control (Ethernet interface view)

priority-flow-control no-drop dot1p

priority-flow-control no-drop dot1p (Ethernet interface view)

Use priority-flow-control no-drop dot1p to enable PFC.

Use undo priority-flow-control no-drop dot1p to disable PFC for 802.1p priorities on an Ethernet interface.

Syntax

priority-flow-control no-drop dot1p dot1p-list

undo priority-flow-control no-drop dot1p

Default

PFC is disabled for all 802.1p priorities on an Ethernet interface.

Views

Ethernet interface view

Predefined user roles

network-admin

Parameters

dot1p-list: Specifies an 802.1p priority (or dot1p priority) list to identify flows that are subject to PFC (for example: 1,3-5). A hyphen (-) connects two numeric values, which together indicate a continuous value range. Different values or value ranges are separated with commas (,). You can configure up to 16 characters for this argument.

Usage guidelines

If you enable PFC and execute this command on both the local and peer devices, the local device will notify the peer device to stop transmitting packets with the specified 802.1p priority when congestion occurs. When congestion is removed, the local device notifies the peer device to transmitting the packets again. This prevents packet loss for traffic with the specified priority. For more information about 802.1p priority, see QoS configuration in ACL and QoS Configuration Guide.

This command is mutually exclusive with the flow-control command or the flow-control receive enable command. For more information about the flow-control and flow-control receive enable commands, see Ethernet interface commands in Layer 2—LAN Switching Command Reference.

If you execute this command multiple times in system view and interface view, the most recent configuration takes effect.

Examples

# Enable PFC in auto mode on GigabitEthernet 1/0/1, and enable PFC for 802.1p priority 5.

<Sysname> system-view

[Sysname] interface gigabitethernet 1/0/1

[Sysname-GigabitEthernet1/0/1] priority-flow-control auto

[Sysname-GigabitEthernet1/0/1] priority-flow-control no-drop dot1p 5

Related commands

display priority-flow-control

flow-control (Interface Command Reference)

flow-control receive enable (Interface Command Reference)

priority-flow-control

priority-flow-control no-drop dot1p (system view)

priority-flow-control no-drop dot1p (system view)

Use priority-flow-control no-drop dot1p to enable PFC for 802.1p priorities on all Ethernet interfaces.

Use undo priority-flow-control no-drop dot1p to disable PFC for 802.1p priorities on all Ethernet interfaces.

Syntax

priority-flow-control no-drop dot1p dot1p-list

undo priority-flow-control no-drop dot1p

Default

PFC is disabled for all 802.1p priorities on all Ethernet interfaces.

Views

System view

Predefined user roles

network-admin

Parameters

dot1p-list: Specifies an 802.1p priority (or dot1p priority) list to identify flows that are subject to PFC (for example: 1,3-5). A hyphen (-) connects two numeric values, which together indicate a continuous value range. Different values or value ranges are separated with commas (,). You can configure up to 16 characters for this argument.

Usage guidelines

The local device notifies the remote end to stop sending packets carrying the specified 802.1p priority if all of the following conditions exist:

·     Both the local end and the remote end have PFC enabled.

·     Both the local end and the remote end have the priority-flow-control no-drop dot1p command configured.

·     The specified 802.1p priority is in the 802.1p priority list specified by the dot1p-list argument.

·     The local end receives packets carrying the specified 802.1p priority, and the received packets cause congestion.

When congestion is eliminated, the local end notifies the remote end to continue to send packets carrying the specified 802.1p priority. In this way, the local device can forward packets carrying 802.1p priorities in the specified 802.1p priority list without packet drops. For more information about the 802.1p priority, see ACL and QoS Configuration Guide.

If you execute this command in system view and Ethernet interface view multiple times, the most recent configuration takes effect.

Examples

# Enable PFC for 802.1p priority 5 globally.

<Sysname> system-view

[Sysname] priority-flow-control no-drop dot1p 5

Related commands

priority-flow-control no-drop dot1p (Ethernet interface view)