In this article we will discuss Switch Forwarding Methods, will make brief discussion on Switch Forwarding Methods, In last article we discuss about Router RIP Configuration Mode.
As networks grew and enterprises began to experience slower network performance, Ethernet bridges (an early version of a switch) were added to networks to limit the size of the collision domains. In the 1990s, advancements in integrated circuit technologies allowed for Ethernet LAN switches to replace Ethernet bridges.
These switches were able to move the Layer 2 forwarding decisions from software to application-specific-integrated circuits (ASICs). ASICs reduce the packet-handling time within the device, and allow the device to handle an increased number of ports without degrading performance. This method of forwarding data frames at Layer 2 was referred to as store-and-forward switching. This term distinguished it from cut-through switching.
Layer 2 Switching Methods. LAN switches are characterized by the forwarding method that they support, such as a store-and-forward switch, cut-through switch, or fragment-free switch.
In the store-and-forward switching method, error checking is performed against the frame, and any frame with errors is discarded.
The store-and-forward method makes a forwarding decision on a frame after it has received the entire frame and checked the frame for errors using a mathematical error-checking mechanism known as a cyclic redundancy check (CRC).
By contrast, the cut-through method, the forwarding process after the destination MAC address of an incoming frame and the egress port has been determined.