set dcb pfc

Use this command to enable or disable PFC for a specified port and priority or to set the link delay allowance.

Syntax

Parameters

Defaults

PFC is disabled on all ports for all priorities by default.

Mode

All command modes.

Usage

Priority Flow Control (PFC) provides for the configuration of a hardware egress queue for flow control. PFC pauses flows by egress queue, not by priority. If non-PFC priorities are mapped to the same egress queue as PFC priorities, the non-PFC priority data will be paused along with the PFC priority data.

Link delay allowance is an ingress priority buffer allotment in bits. This buffer space is used to store final incoming traffic received from the peer before the peer reacts to the PFC frames sent to it, causing the peer to throttle back the traffic. Use the show dcb pfc link-delay-allowance command to determine the current setting.

Valid values for link delay allowance are module dependent and are provided by the CLI help when entering the command.

Note

The link delay allowance setting affects the rate in which PFC frames are invoked. Therefore, it is highly recommended that you not modify the link delay allowance setting unless instructed to by Extreme Networks support.

PFC is disabled for all priorities by default. Given that some packets, such as BPDUs, are sent untagged and can bypass the egress queues, it is strongly recommended that you not apply PFC to the port default priority.

Use the set lldp port tx-tlv priority-flowctrl command to advertise PFC configuration to peers using the LLDP-DCB Priority Flow Control TLV.