DELL 9.8(0.0) User Manual

Page of 1910
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
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
• 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.
Example
Dell(conf-if-Te-1/1)#show config
!
interface TenGigabitEthernet 1/1
no ip address
switchport
no negotiation auto
flowcontrol rx off tx on
no shutdown
...
Example 
(Values)
This Example shows how 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    
Interfaces
797