Ubigate iBG2016 Configuration Guide© SAMSUNG Electronics Co., Ltd. 73CHAPTER 1. Layer-2 SwitchingLayer 2 LAN Switching and BridgingLocal Area Network(LAN) is a data communications network connectingterminals, computers and printers within a building or other geographicallylimited areas. These devices could be connected through wired cables orwireless links. Ethernet and Token Ring are examples of standard LANtechnologies. LAN switching involves examining of physical networkaddresses that uniquely identifies a device in the network. LAN bridgingallows extension of LAN by supporting connection of multiple LAN segments.MAC addresses of the datagram that flow through bridges are examined tobuild a table of known destinations. If the destination of a datagram is on thesame segment as the source of the datagram, the bridge drops the datagrambecause forwarding is not required. However, if the destination is on anothersegment, the bridge transmits the datagram on that segment only. If the bridgedoes not know the destination segment, it transmits the datagram on allsegments except the source segment(a technique known as flooding).IEEE 802.1d-Media Access Control (MAC) Bridging and Spanning-Tree ProtocolMac Bridging allows multiple Local Area Networks(LANs) to be connectedtogether. Transparent bridging involves the creation of MAC address tables,and limits the Ethernet collision domain by filtering data sent between LANsegments. This reduces network congestion and allows networks to bepartitioned for administrative purposes.The Spanning Tree Protocol(STP) calculates the best path between 2 stationswhile preventing loops when multiple paths are available. Multiple pathsamong LAN switches are desirable for redundancy purpose. However, withmultiple paths messages will be duplicated if loops are not care for.
