Summary

This chapter explained the differences between cut-through, store- and-forward, and FragmentFree switching. Cut-through switching provides for low latency but is prone to forwarding errors. Store-and-forward switching eliminates the errors at Layer 2 but has the highest latency. FragmentFree switching reads the first 64 bytes of the frame and has moderate latency and error detection.

Full- and half-duplex Ethernet have differing requirements. Full-duplex Ethernet requires compatible network cards and switched networks but can provide for more bandwidth. Half-duplex Ethernet was originally designed into many networks and only requires hubs.

Fast Ethernet doubles the bandwidth of Ethernet but requires cabling that meets the 100Base specification. However, Fast Ethernet does have distance limitations due to attenuation.

The Spanning-Tree Protocol (STP) was developed to eliminate loops between bridges and switches. Physical loops are often designed into the network for redundancy, but these loops can cause traffic and broadcast problems during operation. STP uses the spanning-tree algorithm (STA) to locate the loops and eliminate them by calculating a best path to the root bridge or switch.

VLANs allow for logical groupings, simplified changes, broadcast control, and security. Layer 3 routing is required for traffic to move between VLANs, and frame tagging is used to track VLAN traffic between network switches.