Service Manual

Command History
This guide is platform-specic. For command information about other platforms, see the relevant Dell Networking
OS Command Line Reference Guide.
Version Description
9.10(0.0) Introduced on the S6100–ON.
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.
9.2(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 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.
• The only conguration 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 congured when the ow control conguration 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 ow control must be o (rx off tx off) before conguring the half duplex.
• Speeds less than 1 Gig cannot be congured when the asymmetric ow control conguration is on. The
following error is returned:
Can’t configure speed <1G when Asymmetric flowcontrol is on, config ignored
• Dell Networking OS only supports rx on tx on and rx off tx off for speeds less than 1 Gig
(Symmetric).
NOTE
: If you use the disable rx flow control command, Dell Networking recommends
rebooting the system.
682 Interfaces