Chapter 10 - TCP/IP Applications. Chapter summary: Bridges selectively relay packets between network segments, depending on their data-link layer destination addresses; bridges maintain a single broadcast domain and create separate collision domains; switches improve on the function of bridges by forwarding packets only to their destination systems;.and other contents. | Chapter Overview Bridging Switching Routing What Is a Bridge? A data-link layer device that connects networks and filters packets Propagates only packets destined for the other side of the bridge Can reduce network traffic and collisions Can lessen delays Connecting LANs with a Bridge Bridges and Collisions A collision domain is a network (or part of a network) that is constructed so that a collision occurs when two computers transmit packets at precisely the same time. Adding a hub to a local area network (LAN) increases its size but maintains a single collision domain because hubs relay signals immediately at the physical layer, without filtering them. Hubs do not relay packets immediately; they wait until the entire packet is received. Because the bridge delays propagation, computers on opposite sides of the bridge transmitting at the same time do not cause a collision. Adding a bridge to a LAN splits it into two collision domains, resulting in fewer collisions and . | Chapter Overview Bridging Switching Routing What Is a Bridge? A data-link layer device that connects networks and filters packets Propagates only packets destined for the other side of the bridge Can reduce network traffic and collisions Can lessen delays Connecting LANs with a Bridge Bridges and Collisions A collision domain is a network (or part of a network) that is constructed so that a collision occurs when two computers transmit packets at precisely the same time. Adding a hub to a local area network (LAN) increases its size but maintains a single collision domain because hubs relay signals immediately at the physical layer, without filtering them. Hubs do not relay packets immediately; they wait until the entire packet is received. Because the bridge delays propagation, computers on opposite sides of the bridge transmitting at the same time do not cause a collision. Adding a bridge to a LAN splits it into two collision domains, resulting in fewer collisions and increased efficiency. Broadcasts Bridges and Broadcasts Bridges propagate all broadcast packets without filtering them. The network segments on either side of a bridge are in the same broadcast domain. Transparent Bridging Transparent bridging is a method for automatically compiling a bridge’s address tables. Bridges maintain an address table for each network segment. Bridges read the source and destination addresses of packets and compare them to the tables to determine whether to propagate them. When a bridge lacks the information needed to filter a packet, it propagates the packet by default. Bridge Types Local bridge. Connects network segments of the same type and at the same location Translation bridge. Connects network segments at the same location that use different media or different protocols Remote bridge. Connects network segments at remote locations, using a wide area network (WAN) link Translation Bridge Switch Characteristics Data-link layer device .
