dcb-pfc - Linux


Overview

dcb-pfc is a versatile tool for managing Data Center Bridging (DCB) priority flow control (PFC) on network interface devices. It offers granular control over PFC settings, allowing network administrators to optimize network performance and prioritize traffic.

Syntax

dcb-pfc [iface] [Options]

Options/Flags

  • -h, –help: Display usage information.
  • -v, –version: Show version information.
  • -e, –enable: Enable PFC on the specified interface.
  • -d, –disable: Disable PFC on the specified interface.
  • -s, –show: Show current PFC settings for the specified interface (default).
  • -t, –tx: Set PFC transmit priority. Valid values: 0-7 (default: 0).
  • -r, –rx: Set PFC receive priority. Valid values: 0-7 (default: 0).
  • -p, –pause: Set PFC pause time. Valid values: 0-65535 (default: 0).
  • -i, –force-en: Force-enable PFC even if the interface does not support it (not recommended in production environments).

Examples

Simple Usage:

  • Display PFC settings for the eth0 interface:
    dcb-pfc eth0
    

Advanced Usage:

  • Enable PFC with transmit priority 3 and pause time 1000 on eth1:

    dcb-pfc -e eth1 -t 3 -p 1000
    
  • Disable PFC on eth2:

    dcb-pfc -d eth2
    

Common Issues

  • If PFC is not enabled on both sides of a network link, it will not work.
  • Forcing PFC on an unsupported interface can lead to network instability.
  • High PFC pause times can increase network latency.

Integration

dcb-pfc can be used in conjunction with other Linux networking tools, such as:

  • ethtool: To set additional network interface parameters.
  • tc: To configure traffic control rules.

Related Commands

  • ethtool
  • tc
  • dcb-setpfc