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● Starts when either the packet pointer or the buffer threshold is met (whichever is met first). When
the discard threshold is met, packets are dropped.
● Ends when both the packet pointer and the buffer threshold fall below 50% of the threshold settings.
The discard threshold defines when the interface starts dropping the packet on the interface. This may
be necessary when a connected device does not honor the flow control frame sent 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.
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:
Cannot configure Asymmetric flowcontrol when speed <1G, config ignored>
● You cannot configure half duplex when the flow control configuration 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 flow control must be off (rx off tx off) before configuring 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 monitor session 5 rx off tx on
no shutdown
...
Example (Values) This Example shows how the Dell Networking OS 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
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
Interfaces
485