- Written by Julie Hakimi
- Posted on January 12, 2026
- Updated on January 12, 2026
- 427 Views
Priority-flow-control (PFC) buffer and history counters provide information on both present PFC pause conditions and past pause events. These buffer counters (since EOS-4.34.2F) and history counters (since EOS-4.35.0F) are available via OpenConfig in addition to the show commands that have existed in previous versions.
- Written by Jared Dulmage
- Posted on October 29, 2025
- Updated on October 29, 2025
- 1238 Views
Priority-Flow-Control (PFC) Fair Adaptive Dynamic Threshold (FADT) configuration facilitates efficient utilization of packet buffer resources for both lossy and lossless traffic. Reserve headroom buffer resources to absorb in-flight packets for congested, lossless flows. Assign default or user-defined PFC profiles to interface/PFC priority pairs, called Priority Groups (PG), to dynamically manage packet buffer usage and assertion of PFC pause.
- Written by Ajay Seshadri
- Posted on June 29, 2023
- Updated on September 1, 2023
- 10605 Views
This document describes the PFC (priority-based flow control) history counters that are available to debug network oversubscription issues. These counters track statistics on the switch that is sending network traffic at a rate that is more than what its peer can handle.
- Written by Ronish Kalia
- Posted on October 9, 2018
- Updated on October 22, 2018
- 11645 Views
DCS 7050X/X2/X3 series. DCS 7060X/X2/X3 series. In previous releases, PFC Watchdog supported only queues
- Written by Corey Hines
- Posted on August 17, 2018
- Updated on November 19, 2024
- 13799 Views
Priority Flow Control is a link-layer flow control mechanism which may be used by an overwhelmed network node to ask its transmitters to stop transmission for a specified period of time. It does so by using special frames known as PFC frames, thus, relieving congestion at the receiver node. With respect to this behavior, PFC is very similar to Link Layer Flow Control ( LLFC ), however, unlike LLFC, PFC allows the overwhelmed node to specify which 802.1Q Class of Service ( CoS ) it wants to stop receiving traffic for. Thus, allowing differentiated treatment of traffic based on CoS.
- Written by Muhammad Yousuf
- Posted on October 22, 2018
- Updated on October 22, 2018
- 10814 Views
Priority Flow Control (PFC) Watchdog feature monitors interfaces for priority flow control Pause storm. If such
- Written by Jared Dulmage
- Posted on July 5, 2024
- Updated on July 17, 2025
- 5732 Views
Priority-based flow control (PFC) buffer counters track ingress port buffer usage for each packet priority. This feature displays the high watermark buffer usage over two time intervals: a polling interval (by default 2 seconds) and the encompassing interval since the counters were cleared. The PFC buffer counter watermarks can be used to expose bursty and transient ingress buffer resource usage. High watermark values indicate congestion conditions that could explain packet loss.
