A Brief Introduction to three switch modes of Cisco switches

When switching data frames, a switch can select different modes to meet network and user needs. Cisco switches provide three switching modes:

Storage forwarding Mode

The Store-and-forward mode means that the switch can complete the entire data frame and perform the forwarding operation only after the CRC verification is passed. If CRC verification fails, that is, the data frame is incorrect, the switch discards the frame. This mode ensures data frame error-free transmission. Of course, the cost is that the transmission delay increases with the length of the data frame.

Fast Forwarding Mode

The Fast-forward (Fast-forward) Mode means that when a switch receives a data frame, it immediately performs the forwarding operation once the destination address is detected. However, because the data frame is not a complete frame during forwarding, the data frame will be directly forwarded without verification or error correction, and the wrong data frame will still be forwarded to the network, this wastes the bandwidth of the network. The advantage of this mode lies in the low latency of data transmission, but the cost is that it cannot perform verification and Error Correction on data frames.

Free segmentation Mode

Free Fragment-free) mode is used when the switch receives a data frame, once it detects that the data frame is not a conflict frlision fragment), the forwarding operation is performed. The conflicted fragment is a data frame fragment damaged by a network conflict. It is characterized by a length less than 64 bytes. Conflicting fragments are not valid data frames and should be discarded. Therefore, the free segmentation mode of the switch is to start forwarding once the received part of the data frame exceeds 64 bytes. The performance of this mode is between the storage forwarding mode and the fast forwarding mode.

1. What is the configuration VLAN of the Cisco ipvst1900 switch?