CLI Guide

tx off Enter the keywords tx off so that flow control frames are not sent from this port to the
connected device when a higher rate of traffic is received.
Defaults
• rx off
• tx off
Command Modes INTERFACE
Supported Modes Programmable-Mux (PMUX)
Full–Switch
Command History
Version Description
9.9(0.0) Introduced on the FN IOM.
9.4(0.0) Supported on the FN I/O Aggregator.
9.2(0.0) Introduced on the M I/O Aggregator.
8.3.16.1 Introduced on the MXL 10/40GbE Switch IO Module.
Usage Information
The globally assigned 48-bit Multicast address 01-80-C2-00-00-01 is used to send and receive pause frames. To
allow full-duplex flow control, stations implementing the pause operation instruct the MAC to enable the
reception of frames with a destination address equal to this multicast address.
The pause:
• Starts when either the packet pointer or the buffer threshold is met (whichever is met first). When the discard
threshold is met, packets are dropped.
• Ends when both the packet pointer and the buffer threshold fall below 50% of the threshold settings.
The discard threshold defines when the interface starts dropping the packet on the interface. This may be
necessary when a connected device does not honor the flow control frame sent by the switch. The discard
threshold should be larger than the buffer threshold so that the buffer holds at least hold at least three packets.
Important Points to Remember
• Do not enable tx pause when buffer carving is enabled. For information and assistance, consult Dell
Networking TAC.
• Asymmetric flow control (rx on tx off, or rx off tx on) setting for the interface port less than 100 Mb/s
speed is not permitted. The following error is returned:
Can’t configure Asymmetric flowcontrol when speed <1G, config ignored
• The only configuration applicable to half duplex ports is rx off tx off. The following error is returned:
Cannot configure Asymmetric flowcontrol when speed <1G, config ignored>
• You cannot configure half duplex when the flow control configuration is on (default is rx on tx on). The
following error is returned:
Cannot configure half duplex when flowcontrol is on, config
ignored
NOTE: The flow control must be off (rx off tx off) before configuring the half duplex.
Interfaces
623