What are the two main forwarding methods used by switches?

Question

Accepted Answer

Store-and-forward switching (receives the entire frame before forwarding) and cut-through switching (forwards immediately after reading the destination MAC (Media Access Control) address).

* Store-and-forward vs cut-through. *

Feature
Store-and-Forward
Cut-Through

Reads
Entire frame
Only up to the destination MAC (first 6 bytes)

Error checking
Yes (checks FCS (Frame Check Sequence)/CRC (Cyclic Redundancy Check))
No

Latency
Higher (must buffer whole frame)
Very low (< 10 μs possible)

Speed mismatch
Handles different port speeds
Cannot handle different speeds

Cisco preferred?
Yes
No (used for low-latency needs)

Both methods use ASICs (Application-Specific Integrated Circuits) for hardware-accelerated switching decisions, which is why switches are so much faster than software-based routing.
Go deeper:

Switch Speeds and Forwarding Methods (Cisco Press) — store-and-forward vs cut-through (fast-forward, fragment-free) and buffering.
 Store-and-Forward vs Cut-Through (NetworkAcademy.IO) — side-by-side latency/error-checking comparison with the verifying CLI.

Feature	Store-and-Forward	Cut-Through
Reads	Entire frame	Only up to the destination MAC (first 6 bytes)
Error checking	Yes (checks FCS (Frame Check Sequence)/CRC (Cyclic Redundancy Check))	No
Latency	Higher (must buffer whole frame)	Very low (< 10 μs possible)
Speed mismatch	Handles different port speeds	Cannot handle different speeds
Cisco preferred?	Yes	No (used for low-latency needs)