Cisco Systems N3KC3064TFAL3 manual Configuring Switching Modes, Information About Switching Modes

C H A P T E R 7

Configuring Switching Modes

This chapter contains the following sections:

•Information About Switching Modes, page 59

•Guidelines and Limitations for Switching Modes, page 60

•Licensing Requirements for Switching Modes, page 60

•Default Settings for Switching Modes, page 61

•Configuring Switching Modes, page 61

•Feature History for Switching Modes, page 62

Information About Switching Modes

The switching mode determines whether the switch begins forwarding the frame as soon as the switch has read the destination details in the packet header or waits until the entire frame has been received and checked for cyclic redundancy check (CRC) errors before forwarding them to the network.

The switching mode is applicable to all packets being switched or routed through the hardware and can be saved persistently through reboots and restarts.

The switch operates in either of the following switching modes:

Cut-Through Switching Mode

Cut-through switching mode is enabled by default. Switches operating in cut-through switching mode start forwarding the frame as soon as the switch has read the destination details in the packet header. A switch in cut-through mode forwards the data before it has completed receiving the entire frame.

The switching speed in cut-through mode is faster than the switching speed in store-and-forward switching mode.

Store-and-Forward Switching Mode

When store-and-forward switching is enabled, the switch checks each frame for cyclic redundancy check (CRC) errors before forwarding them to the network. Each frame is stored until the entire frame has been received and checked.

Cisco Nexus 3000 NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)U3(1)

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