Use the ifconfig flowcontrol option to view and configure flow control settings. You can also use the ifstat command to view the operational flow control setting. If you do not specify the flowcontrol option when configuring a network interface, the configured flow control setting defaults to full.
Flow control can be configured on interfaces operating at or above 1,000 Mbps.
This configured flow control setting is advertised during autonegotiation. If autonegotiation succeeds, the operational flow control setting is determined based on the negotiated speed and the value advertised by the other device. If autonegotiation fails, the configured flow control setting is used