Layer 2 switches are modern bridge products.
A bridge improves performance by keeping local traffic within a limited part of a LAN.
A bridge makes it possible to build a mixed-speed LAN. For example, traffic must be bridged between a 10Mbps segment and a 100Mbps segment.
A bridge can extend the diameter of a LAN.
An Ethernet transparent bridge can dynamically record the port through which a MAC address can be reached in a filtering table. This process is called learning.
Static entries can be configured into a filtering table and used to expedite the forwarding process, impose security constraints, and improve performance by blocking selected frames from entering parts of the LAN.
LAN availability can be improved by installing backup ...