Administrator 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.
pause-threshold Enter the buffer threshold limit for generating PAUSE frames.
resume-offset Enter the offset value for generating PAUSE frames to resume traffic.
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
monitor Enter the keyword monitor then the session-ID to enable mirror flow control frames on
the interface. The range is from 0 to 65535.
Defaults rx on tx off
Command Modes INTERFACE
Command History
This guide is platform-specific. For command information about other platforms, see the relevant Dell EMC
Networking OS Command Line Reference Guide.
Version Description
9.11(0.0) Added support for monitor session.
9.10(0.1) Introduced on the S6010-ON and S4048T-ON.
9.10(0.0) Introduced on the S3148.
9.10(0.0) Introduced on the S6100–ON.
9.8(2.0) Introduced on the S3100 series.
9.8(1.0) Introduced on the Z9100–ON.
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.
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 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.
When a port receives traffic at a higher rate than it can process, the frames are stored in the port buffer. As a
result, buffer usage increases. When the buffer usage reaches the value specified in the “pause-threshold”
argument, the port sends PAUSE frame to the connected link partner to stop sending the traffic. Eventually this
reduces the buffer usage. When the buffer usage drops by the value specified in the “resume-threshold”, the port
again sends a PAUSE frame with 0 as wait-time. This results in resume of the paused traffic flow.
Important Points to Remember
• Do not enable tx pause when buffer carving is enabled. For information and assistance, consult Dell EMC
Networking TAC.
600 Interfaces