Where:rx on: Processes the received flow control frames on this port.rx off: Ignores the received flow control frames on this port.tx on: Sends control frames from this port to the connected device when a higher rate of traffic isreceived.tx off: Flow control frames are not sent from this port to the connected device when a higher rate oftraffic is received.Changes in the flow-control values may not be reflected automatically in show interface output. Todisplay the change, apply the new flow-control setting, shutdown the interface using the shutdowncommand, enable the interface using the no shutdown command, and use the show interfacecommand to verify the changes.Enabling Pause FramesEnable Ethernet pause frames flow control on all ports on a chassis or a line card. If not, the system mayexhibit unpredictable behavior.NOTE: Changes in the flow-control values may not be reflected automatically in the showinterface output. As a workaround, apply the new settings, execute shut then no shut on theinterface, and then check the running-config of the port.NOTE: If you disable rx flow control, Dell Networking recommends rebooting the system.The flow control sender and receiver must be on the same port-pipe. Flow control is not supportedacross different port-pipes.To enable pause frames, use the following command.• Control how the system responds to and generates 802.3x pause frames on 1 and 10 Gig ports.INTERFACE modeflowcontrol rx [off | on] tx [off | on]– rx on: enter the keywords rx on to process the received flow control frames on this port.– rx off: enter the keywords rx off to ignore the received flow control frames on this port.– tx on: enter the keywords tx on to send control frames from this port to the connected devicewhen a higher rate of traffic is received.– tx off: enter the keywords tx off so that flow control frames are not sent from this port to theconnected device when a higher rate of traffic is received.– negotiate: enable pause-negotiation with the egress port of the peer device. If the negotiatecommand is not used, pause-negotiation is disabled. 40 gigabit Ethernet interfaces do not supportpause-negotiation.Configure the MTU Size on an InterfaceIf a packet includes a Layer 2 header, the difference in bytes between the link MTU and IP MTU must beenough to include the Layer 2 header.For example, for VLAN packets, if the IP MTU is 1400, the Link MTU must be no less than 1422:Interfaces 349
