Service Manual

rx off Enter the keywords rx off to ignore the received flow control frames on this
port.
tx on Enter the keywords tx on to send control frames from this port to the connected
device when a higher rate of traffic is received.
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.
Defaults
Command Modes INTERFACE
Command
History
This guide is platform-specific. 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.
9.2(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 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
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
Interfaces 629