Cisco Nexus 9000 Series Configuration Manual page 89

Configuring Switching Modes
This chapter contains the following sections:
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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 (first available in 7.0(3)I1(2)) 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.
Information About Switching Modes, page 75
Guidelines and Limitations for Switching Modes, page 76
Licensing Requirements for Switching Modes, page 77
Default Settings for Switching Modes, page 77
Configuring Switching Modes, page 77
Cisco Nexus 9000 Series NX-OS Layer 2 Switching Configuration Guide, Release 7.x
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