Reference Guide

by the switch. The discard threshold should be larger than the buffer threshold so that the
buffer holds at least hold at least three packets.
Changes in the flow-control values may not be reflected automatically in the show
interface
output. As a workaround, apply the new settings, execute shut then no shut
on the interface, then check the running-config of the port using the show interface
command.
Important Points to Remember
• Do not enable tx pause when buffer carving is enabled. For information and
assistance, consult Dell Networking TAC.
• Asymmetric flow control (rx on tx off, or rx off tx on) setting for the
interface port less than 100 Mb/s speed is not permitted. The following error is
returned:
Can’t configure Asymmetric flowcontrol when speed <1G,
config ignored
• 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 1 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
• FTOS 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.
Example
FTOS(conf-if-gi-0/1)#show config
!
interface GigabitEthernet 0/1
no ip address
switchport
no negotiation auto
flowcontrol rx off tx on
no shutdown
...
Example (Values)
This Example shows how FTOS negotiates the flow control values between two Dell
Networking chassis connected back-to-back using 1G copper ports.
Configured
LocRxConf LocTxConf RemoteRxConf RemoteTxConf
off off off off
off on
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