C H A P T E; Configuring Link Level Flow Control; Link Level Flow Control; Guidelines And Restrictions For Link Level Flow Control - Cisco Nexus 9000 Series Configuration Manual

Configuring Link Level Flow Control

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Link Level Flow Control

Link-level flow control is a congestion management technique that pauses data transmission until the congestion
in the system is resolved. When a receiving device becomes congested, it communicates with the transmitter
by sending a PAUSE frame. When the transmitting device receives a Pause frame it stops the transmission
of any further data frames for a short period of time. The link-level flow control feature applies to all the
traffic on the link. The transmit and receive directions are separately configurable. By default, link-level flow
control is disabled for both directions.

Guidelines and Restrictions for Link Level Flow Control

• show commands with the internal keyword are not supported.
• Link-level flow control (LLFC) is supported on Cisco Nexus 9500 Series switches with Network
• Link-level flow control (LLFC) is supported on Cisco Nexus 9200 Series switches (7.0(3)I3(1) and later
• Beginning with Cisco NX-OS Release 7.0(3)I5(1) and later releases, Link-level flow control (LLFC) is
• The 100G N9K-X9408PC-CFP2 line card does not support link-level flow control (LLFC).
• Ethernet interfaces do not auto-detect the link-level flow control capability. You must configure the
Link Level Flow Control, page 131
Guidelines and Restrictions for Link Level Flow Control, page 131
Information About Link Level Flow Control, page 132
How to Configure Link Level Flow Control, page 133
Configuration Examples for Link Level Flow Control, page 135
Forwarding Engine (NFE) (and Cisco Nexus 3164Q switch with NFE).
releases.
supported on the Cisco Nexus 9300 and 9300-EX Series switches.
capability explicitly.
Cisco Nexus 9000 Series NX-OS Quality of Service Configuration Guide, Release 7.x
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