Licensing Requirements For Priority Flow Control; Prerequisites For Priority Flow Control; Guidelines And Limitations For Priority Flow Control - Cisco Nexus 9000 Series Configuration Manual

Licensing Requirements for Priority Flow Control

Only certain classes of service of traffic can be flow controlled while other classes are allowed to operate
Note
normally.
PFC asks the peer to stop sending frames of a particular CoS value by sending a pause frame to a well-known
multicast address. This pause frame is a one-hop frame that is not forwarded when received by the peer. When
the congestion is mitigated, PFC can request the peer to restart transmitting frames.
RDMA over Converged Ethernet (RoCE) v1 and v2 protocols are supported on Cisco Nexus 9000 Series
Note
switches.

Licensing Requirements for Priority Flow Control

The following table shows the licensing requirements for this feature:
Product
Cisco NX-OS

Prerequisites for Priority Flow Control

PFC has the following prerequisites:
• You must be familiar with using modular QoS CLI.
• You are logged on to the device.

Guidelines and Limitations for Priority Flow Control

PFC has the following configuration guidelines and limitations:
• The show commands with the internal keyword are not supported.
• If PFC is enabled on a port or a port channel, it does not cause a port flap.
• PFC configuration enables PFC in both the send (Tx) and receive (Rx) direction.
• Configuration time quanta of the pause frames is not supported.
• You can configure a PFC watchdog interval to detect whether packets in a no-drop queue are being
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drained within a specified time period. When the time period is exceeded, all outgoing packets are
Configuring Priority Flow Control
License Requirement
The PFC feature does not a require license. Any
feature not included in a license package is bundled
with the NX-OS image and is provided at no extra
charge to you. For a complete explanation of the
Cisco NX-OS licensing scheme, see the
Licensing Guide.
Cisco NX-OS