Priority-Flow-Control No-Drop Dot1P - HP 5900 series Command Reference Manual

priority-flow-control no-drop dot1p

Use priority-flow-control no-drop dot1p to enable PFC for specific 802.1p priorities on an Ethernet
interface.
Use undo priority-flow-control no-drop dot1p to restore the default.
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.
Views
Ethernet interface view
Predefined user roles
network-admin
Parameters
dot1p-list: Specifies an 802.1p priority (or dot1p priority) list to identify flows 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. An 802.1p priority value is in the range of 0 to 7.
Usage guidelines
Suppose PFC is enabled for an 802.1p priority value on both the local end and the peer end. When the
queue of a packet carrying an 802.1 priority is congested, the switch processes the packet according to
its 802.1p priority value as follows:
• If PFC is enabled for the 802.1p priority value, the switch receives the packet and sends a PFC
pause frame to the peer end to notify the peer end to pause sending packets carrying the 802.1p
priority. After the peer end receives the PFC pause frame, it pauses sending packets carrying the
802.1p priority for a period determined by the information in the PFC pause frame. This procedure
is repeated until congestion is removed.
If PFC is not enabled for the 802.1p priority, the switch drops the packet.
•
The relationship between the PFC function and the generic flow control function is shown in
Table 7 The relationship between the PFC function and the generic flow control function
flow-contro
l
Unconfigura
ble
priority-flow-c priority-flow-contro
ontrol enable l no-drop dot1p
Configured Configured
Remarks
You cannot enable flow control by using the
flow-control command on a port where PFC is
enabled and PFC is enabled for the specified
802.1p priority values.
24
Table 7.