Users Guide

• Starts when either the packet pointer or the buer threshold is met (whichever is met rst). When the discard threshold
is met, packets are dropped.
• Ends when both the packet pointer and the buer threshold fall below 50% of the threshold settings.
The discard threshold denes when the interface starts dropping the packet on the interface. This may be necessary when a
connected device does not honor the ow control frame sent by the switch. The discard threshold should be larger than the
buer threshold so that the buer holds at least hold at least three packets.
Important Points to Remember
• Do not enable tx pause when buer carving is enabled. For information and assistance, consult Dell Networking TAC.
• Asymmetric ow 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 conguration applicable to half duplex ports is rx off tx off. The following error is returned:
Cannot configure Asymmetric flowcontrol when speed <1G, config ignored>
• You cannot congure half duplex when the ow control conguration is on (default is rx on tx on). The following
error is returned: Cannot 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.
Example (partial)
Dell(conf-if-tengig-0/1)#show config
!
interface TenGigabitEthernet 0/1
no ip address
switchport
no negotiation auto
flowcontrol rx off tx on
no shutdown
...
Example (Values)
This Example shows how the Dell Networking OS negotiates the ow 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
on off
on on
off on off off
off on
on off
on on
on off off off
off on
on off
on on
on on off off
off on
on off
on on
LocNegRx LocNegTx RemNegRx RemNegTx
off off off off
off off off off
off off off off
off off off off
196
Interfaces