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| Title | Size | Download |
|---|---|---|
| 09-PFC commands | 136.80 KB |
Contents
priority-flow-control (Ethernet interface view)
priority-flow-control (system view)
priority-flow-control deadlock auto-recover action
priority-flow-control deadlock auto-recover cos
priority-flow-control deadlock cos
priority-flow-control deadlock enable
priority-flow-control deadlock precision
priority-flow-control deadlock recover
priority-flow-control deadlock recover-mode
priority-flow-control deadlock threshold
priority-flow-control dot1p headroom
priority-flow-control dot1p ingress-buffer dynamic
priority-flow-control dot1p ingress-buffer static
priority-flow-control dot1p ingress-threshold-offset
priority-flow-control dot1p reserved-buffer
priority-flow-control early-warning inpps
priority-flow-control early-warning outpps
priority-flow-control no-drop dot1p (Ethernet interface view)
priority-flow-control no-drop dot1p (system view)
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
Interface AdminMode OperMode Dot1pList Prio Recv
Send Inpps Outpps
--------------------------------------------------------------------------------
-------------------
WGE1/0/1 Enabled Enabled 0 5
5 3 3
Table 1 Command output
|
Field |
Description |
|
Interface |
Abbreviated name of the interface. |
|
AdminMode |
Administrative PFC status: · Disabled—PFC is disabled for the interface. · Auto—The interface is configured to autonegotiate the PFC status with the remote end. · Enabled—PFC is enabled for the interface. |
|
OperMode |
Operative PFC status: · Disabled—PFC is disabled. · Enabled—PFC is enabled. |
|
Dot1pList |
802.1p priorities that are enabled with PFC. 802.1p priority values 0 through 7 are available. |
|
Prio |
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. |
|
Recv |
Number of received PFC pause frames. |
|
Send |
Number of sent PFC pause frames. |
|
Inpps |
Incoming PFC frame rate in pps for the 802.1p priority. |
|
Outpps |
Outgoing PFC frame rate in pps for the 802.1p priority. |
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 [ receive | send ] }
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.
receive: Enables Rx PFC.
send: Enables Tx 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.
When you enable Rx PFC, the device can receive but cannot send PFC pause frames. When you enable Tx PFC, the device can send but cannot receive PFC pause frames. If neither receive nor send is specified, this command enables both Rx PFC and Tx PFC.
If you execute this command in system view and Ethernet interface view multiple times, the most recent configuration takes effect.
Examples
# Enable PFC on Twenty-FiveGigE 1/0/1.
<Sysname> system-view
[Sysname] interface twenty-fivegige 1/0/1
[Sysname-Twenty-FiveGigE1/0/1] 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 [ receive | send ] }
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.
receive: Enables Rx PFC.
send: Enables Tx 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.
When you enable Rx PFC, the device can receive but cannot send PFC pause frames. When you enable Tx PFC, the device can send but cannot receive PFC pause frames. If neither receive nor send is specified, this command enables both Rx PFC and Tx PFC.
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 deadlock auto-recover action
Use priority-flow-control deadlock auto-recover action to configure the action to take on packets during the delay timer period for PFC deadlock detection automatic recovery.
Use undo priority-flow-control deadlock auto-recover action to restore the default.
Syntax
priority-flow-control deadlock auto-recover action { discard | forwarding }
undo priority-flow-control deadlock auto-recover action
Default
The device forwards the received data packets during the delay timer period for PFC deadlock detection automatic recovery.
Views
System view
Predefined user roles
network-admin
Parameters
discard: Drops the received data packets.
forwarding: Forwards the received data packets.
Usage guidelines
When the device enters the PFC deadlock state, you can use this command to configure the device to drop or forward received data packets during the delay timer period for PFC deadlock detection automatic recovery.
Examples
# Configure the device to drop received data packets during the delay timer period for PFC deadlock detection automatic recovery.
<Sysname> system-view
[Sysname] priority-flow-control deadlock auto-recover action discard
Related commands
priority-flow-control deadlock cos
priority-flow-control deadlock enable
priority-flow-control deadlock auto-recover cos
Use priority-flow-control deadlock auto-recover cos to configure the delay timer for PFC deadlock detection automatic recovery.
Use undo priority-flow-control deadlock auto-recover cos to delete the delay timer for PFC deadlock detection automatic recovery.
Syntax
priority-flow-control deadlock auto-recover slot slot-number cos cos-value delay delay-interval
undo priority-flow-control deadlock auto-recover slot slot-number cos [ cos-value ]
Default
The delay timer for PFC deadlock detection automatic recovery is not configured.
Views
System view
Predefined user roles
network-admin
Parameters
cos cos-value: Specifies the CoS value of packets, in the range of 0 to 7. Different CoS values correspond to different 802.1p priority values. To see the CoS-to-802.1p mapping, execute the display qos map-table dot1p-lp command.
delay delay-interval: Specifies the delay timer for PFC deadlock detection automatic recovery. The value range for the delay timer is 1 to 15.
slot slot-number: Specifies the slot number of the device, which is fixed at 1.
Usage guidelines
PFC deadlock detection periodically detects whether deadlock occurs to packets carrying the specified CoS value. If the device enters the PFC deadlock state and PFC deadlock detection is recovered in automatic mode, the device automatically recovers PFC deadlock detection after the delay timer expires. The delay timer is determined by this command and the PFC deadlock detection timer precision.
This command takes effect only in automatic recovery mode.
The specified CoS value must be within the 802.1p priority values configured by using the priority-flow-control no-drop dot1p command.
You can set the same delay timer for different CoS values.
If you execute this command multiple times for the same CoS value, the most recent configuration takes effect.
Examples
# Set the delay timer for PFC deadlock detection automatic recovery to 5 for packets carrying CoS value 7.
<Sysname> system-view
[Sysname] priority-flow-control deadlock auto-recover slot 1 cos 7 delay 5
Related commands
display qos map-table dot1p-lp (ACL and QoS Command Reference)
priority-flow-control deadlock precision
priority-flow-control no-drop dot1p
priority-flow-control deadlock cos
Use priority-flow-control deadlock cos to set the PFC deadlock detection interval for the specified CoS value.
Use undo priority-flow-control deadlock cos to delete the PFC deadlock detection interval for the specified CoS value or all CoS values.
Syntax
priority-flow-control deadlock slot slot-number cos cos-value interval interval
undo priority-flow-control deadlock slot slot-number cos [ cos-value ]
Default
The PFC deadlock detection interval for a CoS value is not set.
Views
System view
Predefined user roles
network-admin
Parameters
cos cos-value: Specifies the CoS value of packets, in the range of 0 to 7.
interval interval: Specifies the PFC deadlock detection interval in the range of 1 to 15.
If you do not specify this keyword, the PFC feature and PFC deadlock detection feature are automatically recovered on an interface when the detection interval expires, no matter whether the interface receives PFC pause frames.
slot slot-number: Specifies the slot number of the device, which is fixed at 1.
Usage guidelines
The PFC deadlock detection feature periodically detects whether deadlock occurs to packets that carry the specified CoS value. To obtain the length of time for the detection interval, multiply the detection interval by the precision of the PFC deadlock detection timer.
The specified CoS value must be within the 802.1p priority list specified by using the priority-flow-control no-drop dot1p command. To view the 802.1p priority for each CoS value, execute the display qos map-table dot1p-lp command.
You can set the same detection interval for different CoS values.
If you execute this command for the same CoS value multiple times, the most recent configuration takes effect.
Examples
# Set the PFC deadlock detection interval to 5 for packets carrying CoS value 7 on slot 1.
<Sysname> system-view
[Sysname] priority-flow-control deadlock slot 1 cos 7 interval 5
Related commands
display qos map-table dot1p-lp (ACL and QoS Command Reference)
priority-flow-control deadlock precision
priority-flow-control no-drop dot1p
priority-flow-control deadlock enable
Use priority-flow-control deadlock enable to enable PFC deadlock detection on an interface.
Use undo priority-flow-control deadlock enable to disable PFC deadlock detection on an interface.
Syntax
priority-flow-control deadlock enable
undo priority-flow-control deadlock enable
Default
PFC deadlock detection is disabled on an interface.
Views
Ethernet interface view
Predefined user roles
network-admin
Usage guidelines
The device enters the PFC deadlock state if the following conditions exist on an interface:
· PFC for 802.1p priorities is enabled by using the priority-flow-control and priority-flow-control no-drop dot1p commands.
· Packets carrying the specified 802.1p priority are transmitted in a loop.
· No packets in the data buffer can be forwarded.
This command enables periodically detecting whether the device is in PFC deadlock state.
Examples
# Enable PFC deadlock detection on Twenty-FiveGigE 1/0/1.
<Sysname> system-view
[Sysname] interface twenty-fivegige 1/0/1
[Sysname-Twenty-FiveGigE1/0/1] priority-flow-control deadlock enable
Related commands
priority-flow-control
priority-flow-control deadlock cos
priority-flow-control no-drop dot1p
priority-flow-control deadlock precision
Use priority-flow-control deadlock precision to set the precision for the PFC deadlock detection timer.
Use undo priority-flow-control deadlock precision to restore the default.
Syntax
priority-flow-control deadlock slot slot-number precision { high | low | normal }
undo priority-flow-control deadlock slot slot-number precision
Default
The PFC deadlock detection timer uses normal precision.
Views
System view
Predefined user roles
network-admin
Parameters
high: Specifies the high precision for the PFC deadlock detection timer.
low: Specifies the low precision for the PFC deadlock detection timer.
normal: Specifies the normal precision for the PFC deadlock detection timer.
slot slot-number: Specifies the slot number of the device, which is fixed at 1.
Usage guidelines
Use this command to adjust the precision for the PFC deadlock detection timer and change the PFC deadlock detection interval.
If you execute this command multiple times, the most recent configuration takes effect.
Examples
# Set the high precision for the PFC deadlock detection timer on slot 1.
<Sysname> system-view
[Sysname] priority-flow-control deadlock slot 1 precision high
priority-flow-control deadlock recover
Use priority-flow-control deadlock recover to recover PFC deadlock detection on an interface.
Syntax
priority-flow-control deadlock recover
Views
Ethernet interface view
Predefined user roles
network-admin
Usage guidelines
The device can automatically release the deadlock state, but both the PFC deadlock detection and PFC features are disabled on the interface at the same time. To manually recover PFC deadlock detection on the interface, execute this command after setting the manual recovery mode for PFC deadlock detection on the interface. The PFC feature is also enabled again when you execute this command.
Examples
# Recover PFC deadlock detection on Twenty-FiveGigE 1/0/1.
<Sysname> system-view
[Sysname] interface twenty-fivegige 1/0/1
[Sysname-Twenty-FiveGigE1/0/1] priority-flow-control deadlock recover
Related commands
priority-flow-control deadlock recover-mode
priority-flow-control deadlock recover-mode
Use priority-flow-control deadlock recover-mode to set the recovery mode for PFC deadlock detection on an interface.
Use undo priority-flow-control deadlock recover-mode to restore the default.
Syntax
priority-flow-control deadlock recover-mode { auto | manual }
undo priority-flow-control deadlock recover-mode
Default
PFC deadlock detection recovers in automatic mode on an interface.
Views
Ethernet interface view
Predefined user roles
network-admin
Parameters
auto: Specifies the automatic recovery mode.
manual: Specifies the manual recovery mode.
Usage guidelines
When the PFC deadlock state is detected and PFC deadlock detection is recovered in automatic mode, the device automatically releases the deadlock state and recovers PFC and PFC deadlock detection after the delay timer expires. Within the delay timer period, the device disables PFC and PFC deadlock detection on the interface, so that packets can be forwarded properly. PFC deadlock detection can be recovered in automatic or manual mode on the interface. Recovering this feature enables the PFC feature again at the same time. Use the automatic recovery mode when no serious failures occur.
When a packet loop cannot be resolved and the device enters the PFC deadlock state frequently, manually recover PFC deadlock detection on the interface as follows:
1. Perform troubleshooting and set the manual recovery mode for PFC deadlock detection.
2. Execute the priority-flow-control deadlock recover command to recover the PFC deadlock detection and PFC features.
Examples
# Set the manual recovery mode for PFC deadlock detection on Twenty-FiveGigE 1/0/1.
<Sysname> system-view
[Sysname] interface twenty-fivegige 1/0/1
[Sysname-Twenty-FiveGigE1/0/1] priority-flow-control deadlock recover-mode manual
Related commands
priority-flow-control deadlock recover
priority-flow-control deadlock threshold
Use priority-flow-control deadlock threshold to configure the upper threshold for PFC deadlock times within the specified period.
Use undo priority-flow-control deadlock threshold to restore the default.
Syntax
priority-flow-control deadlock threshold slot slot-number cos cos-value period period count count
undo priority-flow-control deadlock threshold slot slot-number cos [ cos-value ]
Default
The upper threshold for PFC deadlock times within the specified period is not configured.
Views
System view
Predefined user roles
network-admin
Parameters
cos cos-value: Specifies the CoS value of packets, in the range of 0 to 7. Different CoS values correspond to different 802.1p priority values. To see the CoS-to-802.1p mapping, execute the display qos map-table dot1p-lp command.
period period: Specifies the period for detecting PFC deadlock times, in seconds. The value range for this parameter is 1 to 60.
count count: Specifies the upper threshold for PFC deadlock times within the specified period. The value range for this parameter is 1 to 500.
slot slot-number: Specifies the slot number of the device, which is fixed at 1.
Usage guidelines
With this command configured, when the PFC deadlock times within the specified period exceed the upper threshold on an interface, the device disables PFC for the corresponding 802.1p priority on the interface. To recover the PFC feature on the interface in this case, execute the undo priority-flow-control deadlock threshold command.
The detection period specified in this command must be longer than the PFC deadlock detection interval configured by using the priority-flow-control deadlock cos command, so that you can determine whether the device frequently enters the PFC deadlock state.
The specified CoS value must be within the 802.1p priority values configured by using the priority-flow-control no-drop dot1p command.
You can set the same detection period for different CoS values.
If you execute this command multiple times for the same CoS value, the most recent configuration takes effect.
Examples
# Set the upper threshold for PFC deadlock times to 100 within the period of 5 seconds.
<Sysname> system-view
[Sysname] priority-flow-control deadlock threshold slot 1 cos 7 period 5 count 100
Related commands
priority-flow-control deadlock cos
priority-flow-control no-drop dot1p
priority-flow-control dot1p headroom
Use priority-flow-control dot1p headroom to set the headroom buffer threshold.
Use undo priority-flow-control dot1p headroom to restore the default.
Syntax
priority-flow-control dot1p dot1p headroom headroom-number
undo priority-flow-control dot1p dot1p headroom
Default
The headroom buffer threshold is not set.
Views
Ethernet interface view
Predefined user roles
network-admin
Parameters
dot1p: Specifies an 802.1p priority in the range of 0 to 7.
headroom-number: Specifies the headroom buffer threshold. The value range is 128 to 393216.
Usage guidelines
Before executing this command, you must use the priority-flow-control no-drop dot1p command to enable PFC for the specified 802.1p priority and use the priority-flow-control enable command to enable PFC on the specified interface.
If you execute this command or the priority-flow-control no-drop dot1p (Ethernet interface view) command multiple times for the same 802.1p priority, the headroom-number argument in the most recent command takes effect.
When two directly connected interfaces transmit data, the buffers of interfaces are used for buffering received data. A longer transmission distances needs a large buffer size. You can use this command to set the headroom buffer threshold to implement zero packet loss.
Examples
# Set the headroom buffer threshold to 1000 for 802.1p priority 1.
<sysname> system-view
[Sysname] interface twenty-fivegige 1/0/1
[Sysname-Twenty-FiveGigE1/0/1] priority-flow-control dot1p 1 headroom 1000
Related commands
priority-flow-control (Ethernet interface view)
priority-flow-control (System view)
priority-flow-control no-drop dot1p
priority-flow-control dot1p ingress-buffer dynamic
Use priority-flow-control dot1p ingress-buffer dynamic to set the dynamic back pressure frame triggering threshold.
Use undo priority-flow-control dot1p ingress-buffer to restore the default.
Syntax
priority-flow-control dot1p dot1p ingress-buffer dynamic ratio
undo priority-flow-control dot1p dot1p ingress-buffer
Default
The dynamic back pressure frame triggering threshold is not set.
Views
Ethernet interface view
Predefined user roles
network-admin
Parameters
dot1p: Specifies an 802.1p priority in the range of 0 to 7.
ratio: Specifies the dynamic back pressure frame triggering threshold in percentage. The value range for this argument is 1 to 90.
Usage guidelines
Before executing this command, you must use the priority-flow-control no-drop dot1p command to enable PFC for the specified 802.1p priority and use the priority-flow-control enable command to enable PFC on the specified interface.
If you execute this command multiple times for the same 802.1p priority, the most recent configuration takes effect.
Examples
# Set the dynamic back pressure frame triggering threshold to 30 for 802.1p priority 1.
<sysname> system-view
[Sysname] interface twenty-fivegige 1/0/1
[Sysname-Twenty-FiveGigE1/0/1] priority-flow-control dot1p 1 ingress-buffer dynamic 30
Related commands
priority-flow-control (Ethernet interface view)
priority-flow-control (System view)
priority-flow-control no-drop dot1p
priority-flow-control dot1p ingress-buffer static
Use priority-flow-control dot1p ingress-buffer static to set the static back pressure frame triggering threshold.
Use undo priority-flow-control dot1p ingress-buffer to restore the default.
Syntax
priority-flow-control dot1p dot1p-list ingress-buffer static threshold
undo priority-flow-control dot1p dot1p-list ingress-buffer
Default
The static back pressure frame triggering threshold is not set.
Views
Ethernet interface view
Predefined user roles
network-admin
Parameters
dot1p: Specifies an 802.1p priority in the range of 0 to 7.
threshold: Specifies the static back pressure frame triggering threshold. The value range is 128 to 196608.
Usage guidelines
Before executing this command, you must use the priority-flow-control no-drop dot1p command to enable PFC for the specified 802.1p priority and use the priority-flow-control enable command to enable PFC on the specified interface.
If you execute this command for the same 802.1p priority multiple times, the most recent configuration takes effect.
Examples
# Set the static back pressure frame triggering threshold to 1000 for 802.1p priority 1.
<sysname> system-view
[Sysname] interface twenty-fivegige 1/0/1
[Sysname-Twenty-FiveGigE1/0/1] priority-flow-control dot1p 1 ingress-buffer static 1000
Related commands
priority-flow-control (Ethernet interface view)
priority-flow-control (System view)
priority-flow-control no-drop dot1p
priority-flow-control dot1p ingress-threshold-offset
Use priority-flow-control dot1p ingress-threshold-offset to set the offset between the back pressure frame stopping threshold and triggering threshold.
Use undo priority-flow-control dot1p ingress-threshold-offset to restore the default.
Syntax
priority-flow-control dot1p dot1p ingress-threshold-offset offset-number
undo priority-flow-control dot1p dot1p ingress-threshold-offset
Default
The offset between the back pressure frame stopping threshold and triggering threshold is not set.
Views
Ethernet interface view
Predefined user roles
network-admin
Parameters
dot1p: Specifies an 802.1p priority in the range of 0 to 7.
offset-number: Specifies the offset between the back pressure frame stopping threshold and triggering threshold. The value range is 128 to 196608.
Usage guidelines
Before executing this command, you must use the priority-flow-control no-drop dot1p command to enable PFC for the specified 802.1p priority and use the priority-flow-control enable command to enable PFC on the specified interface.
If you execute this command multiple times, the most recent configuration takes effect.
Examples
# Set the offset between the back pressure frame stopping threshold and triggering threshold to 1000 for 802.1p priority 1.
<sysname> system-view
[Sysname] interface twenty-fivegige 1/0/1
[Sysname-Twenty-FiveGigE1/0/1] priority-flow-control dot1p 1 ingress-threshold-offset 1000
Related commands
priority-flow-control (Ethernet interface view)
priority-flow-control (System view)
priority-flow-control no-drop dot1p
priority-flow-control dot1p reserved-buffer
Use priority-flow-control dot1p reserved-buffer to set the PFC reserved threshold.
Use undo priority-flow-control dot1p reserved-buffer to restore the default.
Syntax
priority-flow-control dot1p dot1p reserved-buffer reserved-number
undo priority-flow-control dot1p dot1p reserved-buffer
Default
The PFC reserved threshold is not set.
Views
Ethernet interface view
Predefined user roles
network-admin
Parameters
dot1p: Specifies an 802.1p priority in the range of 0 to 7.
reserved-number: Specifies the PFC reserved threshold. The value range is 128 to 196608.
Usage guidelines
Before executing this command, you must use the priority-flow-control no-drop dot1p command to enable PFC for the specified 802.1p priority and use the priority-flow-control enable command to enable PFC on the specified interface.
If you execute this command or the priority-flow-control no-drop dot1p (Ethernet interface view) command multiple times for the same 802.1p priority, the reserved-number argument in the most recent command takes effect.
Examples
# Set the PFC reserved threshold to 1000 for 802.1p priority 1.
<sysname> system-view
[Sysname] interface twenty-fivegige 1/0/1
[Sysname-Twenty-FiveGigE1/0/1] priority-flow-control dot1p 1 reserved-buffer 1000
Related commands
priority-flow-control (Ethernet interface view)
priority-flow-control (System view)
priority-flow-control no-drop dot1p
priority-flow-control early-warning inpps
Use priority-flow-control early-warning inpps to configure the early warning threshold for incoming PFC packets.
Use undo priority-flow-control early-warning inpps to delete the early warning threshold for incoming PFC packets.
Syntax
priority-flow-control early-warning dot1p dot1p-list inpps pps-value
undo priority-flow-control early-warning [ dot1p dot1p-list ] inpps
Default
No early warning threshold is configured for incoming PFC packets.
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.
inpps pps-value: Specifies the number of PFC frames that an interface can receive in pps, in the range of 1 to 159783010.
Usage guidelines
You can configure the early warning threshold for incoming or outgoing PFC packets of an interface as needed. The early warning threshold notifies a situation where the PFC packet transmission rate is still within a normal range but needs attention.
When the rate of PFC packets that an interface sends or receives reaches the early warning threshold, the system generates traps and logs to notify the user. According to the traps and logs, the user can discover some exceptions in the network, for example:
· The NIC of the peer device fails and continuously sends PFC packets at a high speed. In this case, you can set the early warning threshold for incoming PFC packets.
· The device fails and continuously sends PFC frames. In this case, you can set the early warning threshold for outgoing PFC packets.
To monitor bidirectional PFC packets, you can set the early warning thresholds for incoming packets and outgoing packets separately.
The number of PFC pause frames that an interface receives is counted and the early warning threshold configuration takes effect only when PFC is enabled.
If you execute this command multiple times, the most recent configuration takes effect.
Examples
# Set the early warning threshold to 80 pps for incoming PFC packets with 802.1p priority value 7 on Twenty-FiveGigE 1/0/1.
<Sysname> system-view
[Sysname] interface twenty-fivegige 1/0/1
[Sysname-Twenty-FiveGigE1/0/1] priority-flow-control early-warning dot1p 7 inpps 80
priority-flow-control early-warning outpps
Use priority-flow-control early-warning outpps to configure the early warning threshold for outgoing PFC packets.
Use undo priority-flow-control early-warning outpps to delete the early warning threshold for outgoing PFC packets.
Syntax
priority-flow-control early-warning dot1p dot1p-list outpps pps-value
undo priority-flow-control early-warning [ dot1p dot1p-list ] outpps
Default
No early warning threshold is configured for outgoing PFC packets.
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.
outpps pps-value: Specifies the number of PFC frames that an interface can send in pps, in the range of 1 to 159783010.
Usage guidelines
You can configure the early warning threshold for incoming or outgoing PFC packets of an interface as needed. The early warning threshold notifies a situation where the PFC packet transmission rate is still within a normal range but needs attention.
When the rate of PFC packets that an interface sends or receives reaches the early warning threshold, the system generates traps and logs to notify the user. According to the traps and logs, the user can discover some exceptions in the network, for example:
· The NIC of the peer device fails and continuously sends PFC packets at a high speed. In this case, you can set the early warning threshold for incoming PFC packets.
· The device fails and continuously sends PFC frames. In this case, you can set the early warning threshold for outgoing PFC packets.
To monitor bidirectional PFC packets, you can set the early warning thresholds for incoming packets and outgoing packets separately.
The number of PFC pause frames that an interface sends is counted and the early warning threshold configuration takes effect only when PFC is enabled.
If you execute this command multiple times, the most recent configuration takes effect.
Examples
# Set the early warning threshold to 50 pps for outgoing PFC packets with 802.1p priority value 1 on Twenty-FiveGigE 1/0/1.
<Sysname> system-view
[Sysname] interface twenty-fivegige 1/0/1
[Sysname-Twenty-FiveGigE1/0/1] priority-flow-control early-warning dot1p 1 outpps 50
priority-flow-control no-drop dot1p (Ethernet interface view)
Use priority-flow-control no-drop dot1p to enable PFC and configure PFC thresholds for 802.1p priorities on an Ethernet interface.
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 [ pause-threshold { threshold-value | ratio threshold-ratio } [ headroom headroom-value | pause-threshold-offset offset-value | reserved-buffer reserved-value ] * ]
undo priority-flow-control no-drop dot1p [ dot1p dot1p-list ]
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. If you do not specify this argument in the undo form, the undo form disables PFC for all 802.1p priorities.
pause-threshold: Specifies the back pressure frame triggering threshold. If you do not specify this keyword, all PFC thresholds use their defaults.
threshold-value: Specifies the back pressure frame triggering threshold in absolute value. The value range is 128 to 196608.
ratio threshold-ratio: Specifies the back pressure frame triggering threshold in percentage. The value range is 1 to 90.
headroom headroom-value Specifies the maximum number of cell resources that can be used in the headroom storage space for queues. The value range is 128 to 393216.
pause-threshold-offset offset-value: Specifies the offset between the back pressure frame stopping threshold and triggering threshold. The value range depends on the value for the threshold-value argument. For more information, see the prompt message on the device.
reserved-buffer reserved-value: Specifies the PFC reserved threshold for queues. The value range is 128 to 196608.
Usage guidelines
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CAUTION: · After PFC for 802.1p priorities is enabled, each PFC threshold mentioned above uses a default value, which is adequate in typical network environments. As a practice, do not change the default value. · The offset between the back pressure frame stopping threshold and triggering threshold cannot be greater than the back pressure frame triggering threshold. |
Setting PFC thresholds enables flexible control over PFC and can make good use of the storage spaces. The device supports the following PFC thresholds:
· Headroom buffer threshold—Maximum cell resources that can be used by packets with the specified 802.1p priority values in a headroom storage space. An interface drops received packets once this threshold is reached.
· Back pressure frame triggering threshold—Maximum cell resources that can be used by packets with the specified 802.1p priority values in a shared storage space. PFC is triggered once this threshold is reached. The back pressure frame triggering threshold can be configured in the following methods:
¡ Absolute value—Maximum cell resources set in absolute value (static back pressure frame triggering threshold).
¡ Percentage—Maximum cell resources set in percentage (dynamic back pressure frame triggering threshold).
· Offset between the back pressure frame stopping threshold and triggering threshold—When the number of cell resources used by packets with a specific 802.1p priority value decreases by this offset after PFC is triggered, PFC will be stopped.
· PFC reserved threshold—Number of cell resources reserved for packets with the specified 802.1p priority values in a guaranteed storage space.
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 Twenty-FiveGigE 1/0/1, and enable PFC for 802.1p priority 5.
<Sysname> system-view
[Sysname] interface twenty-fivegige 1/0/1
[Sysname-Twenty-FiveGigE1/0/1] priority-flow-control auto
[Sysname-Twenty-FiveGigE1/0/1] priority-flow-control no-drop dot1p 5
Related commands
display priority-flow-control
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)
