03-Layer 2—LAN Switching Configuration Guide

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18-Cut-through Layer 2 forwarding configuration

Configuring cut-through Layer 2 forwarding

About cut-through Layer 2 forwarding

A cut-through forwarding-enabled device forwards a frame after it receives the first 64 bytes of the frame. This feature reduces the transmission time of a frame and enhances forwarding performance.

Restrictions and guidelines for cut-through Layer 2 forwarding configuration

With cut-through forwarding, the device forwards CRC-error frames because it starts forwarding frames before their CRC field is received.

This feature is not available on the following ports:

·     The two SFP+ ports on the front panel of an S6820-32H switch.

·     The two SFP ports on the back panel of an S6820-56HF or S6820-4C switch.


1.     Enter system view.


2.     Enable cut-through forwarding.

cut-through enable

By default, cut-through forwarding is disabled.