1) cut-through: through Ethernet switch can be understood as the way in which the port is crisscrossed circuit matrix between the telephone switchboard. It detected in the input port when a packet, check the package in baotou, for the purpose of the package address, start the internal dynamic lookup table into the corresponding output port, the intersections on the input and output, the packets through the corresponding port, realize the exchange function. Because do not need to be stored, delay is very small, exchange, very fast, this is its advantage. Its disadvantage is that because the packet content has not been Ethernet switch, so can't check whether the transmission of packets is wrong, does not provide error detection ability. Since there is no cache, will not have different rate of input/output port connected directly, and easy to lost package.

2) store and forward: store-and-forward mode is the most widely used computer network field. It put the input port of packet storage first, and then the examination of the CRC (cyclic redundancy check), take out only after the error packet processing packets to the destination address, by a lookup table is transformed into output port to send out the package. Because of this, store-and-forward mode in the data processing time delay, this is the lack of it, but it can be to enter switches the packets for error detection, effectively improve network performance. Particularly important is that it can support the transformation between the different velocity of port, keep high speed between the port and low-speed port work together.

3) pieces of isolation: this is a solution between the former two. It checks whether the length of the packet is enough 64 bytes, if less than 64 bytes, that is a fake bag, it discards the package; If more than 64 bytes, the packet is sent. This approach also does not provide data validation. It's faster than a store-and-forward method of data processing, but slower than straight through.