Users Guide

tx on Enter the keywords tx on to send control frames from this port to the connected
device when a higher rate of trac is received.
tx o Enter the keywords tx off so that ow control frames are not sent from this
port to the connected device when a higher rate of trac is received.
negotiate (Optional) Enter the keyword negotiate to enable the pause-negotiation with
the egress port of the peer device. If the negotiate command is not used,
pause-negotiation is disabled. 40 gigabit Ethernet interfaces do not support pause-
negotiation
Defaults rx on tx o
Command Modes INTERFACE
Command History
This guide is platform-specic. For command information about other platforms, refer to the relevant Dell
Networking OS Command Line Reference Guide.
The following is a list of the Dell Networking OS version history for this command.
Version Description
9.8(0.0P5) Introduced on the S4048-ON.
9.8(0.0P2) Introduced on the S3048-ON.
9.7(0.0) Introduced on the S6000-ON.
9.6.0.0 Added support for the negotiate feature on the S4810 and S4820T.
9.2(1.0) Introduced on the Z9500.
9.0.2.0 Introduced on the S6000.
8.3.19.0 Introduced on the S4820T.
8.3.11.1 Introduced on the Z9000.
8.3.7.0 Introduced on the S4810.
8.1.1.0 Introduced on the E-Series ExaScale.
6.5.1.9 and 7.4.1.0 Introduced on the E-Series.
7.8.1.0 Introduced on the C-Series and S-Series with the thresholds option.
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 ow control, stations implementing the pause operation instruct the MAC to
enable the reception of frames with a destination address equal to this multicast address.
When a port receives trac at a higher rate than it can process, the frames are stored in the port buer. As
a result, buer usage increases. When the buer usage reaches the value specied in the “pause-threshold”
argument, the port sends PAUSE frame to the connected link partner to stop sending the trac. Eventually
this reduces the buer usage. When the buer usage drops by the value specied in the “resume-
threshold”, the port again sends a PAUSE frame with 0 as wait-time. This results in resume of the paused
trac ow.
Important Points to Remember
• Do not enable tx pause when buer carving is enabled. For information and assistance, consult Dell
Networking TAC.
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Interfaces