CLI Guide

Version Description
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.
● The only configuration applicable to half duplex ports is rx off tx off. The following error is
returned:
Can’t configure flowcontrol when half duplex is configure, config ignored
● Half duplex cannot be configured when the flow control configuration is on (default is rx on tx
on). The following error is returned:
Can’t 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.
● Speeds less than one Gig cannot be configured when the asymmetric flow control configuration is on.
The following error is returned:
Can’t configure speed <1G when Asymmetric flowcontrol is on, config
ignored
● Dell EMC Networking OS only supports rx on tx on and rx off tx off for speeds less than
one Gig (Symmetric).
NOTE:
If you use the disable rx flow control command, Dell EMC Networking recommends
rebooting the system.
NOTE: Dell EMC Networking OS does not support mirroring of tx pause frames.
Interfaces 687