Module 2 PDF

MODULE 2 1 Company with Many Standalone Computers 2 A Simple LAN 3 LAN: Local Area Network 4 WAN: Wide Area Network 5 Examples of Data Networks 6 Networking...

MODULE 2 1 Company with Many Standalone Computers 2 A Simple LAN 3 LAN: Local Area Network 4 WAN: Wide Area Network 5 Examples of Data Networks 6 Networking Devices  Equipment that connects to a network segment is called a device  These devices are broken into two classifications ⚫ End user devices—Includes computers, printers, scanners ⚫ Network devices—Includes devices that connect the end-user devices to allow them to communicate 7 End User Devices 8 Network Devices 9 Repeaters 10 Network Interface Cards Each NIC made has a unique Media Access Control (MAC) address Operates on Layer 2 of the OSI Model The MAC address controls data communications for the host on the LAN 11  Bridges Bridges convert network data formats and perform basic data transmission management Bridges provide connections between LANs They also check data to determine if it should cross the bridge; this makes each part of the network more efficient 12 Bridges  A broadcast is a data packet that is sent to all nodes on a network  A broadcast domain consists of all the devices connected to a network that receive the data packet broadcast by a node to all other nodes on the same network  Bridges always forward all broadcasts  Segments in a bridged environment are considered to be in the same broadcast domain 13  Bridges  A bridge is a Layer 2 device designed to create two or more LAN segments, each of which is a separate collision domain  Designed to create more usable bandwidth  The purpose of a bridge is to filter traffic on a LAN to keep local traffic local yet allow connectivity to other segments of the LAN 14  Hubs In Ethernet networks:  A collision occurs when two bits propagate at the same time on the same network  The area within the network from where the data packets originate and collide is called a collision domain 15  Switches Workgroup switches add more intelligence to data transfer management They can determine if data should remain on a LAN and transfer data only to the connection that needs it Another difference between a bridge and switch is that a switch does not convert data transmission formats 16 Layer 2 Switches  Called LAN switches or workgroup switches  Same properties as a bridge, but operate at a higher speeds  Think of each switch port as a microbridge  Each port gives each host the medium’s full bandwidth, called microsegmentation 17 Routers Routers can regenerate signals, concentrate multiple connections, convert data transmission formats, and manage data transfers They can also connect to a WAN, which allows them to connect LANs that are separated by great distances None of the other devices can provide this type of connection 18 Routers A router is a network device that passes data packets between networks based on Layer 3 addresses Routers can make decisions regarding the best path for delivery of data on the network because routers forward data based on network address Unlike switches and bridges, routers know the location where to send data 19 Network Topology  Network topology defines the structure of the network  Physical topologies ⚫ Define the actual layout of the wire (media)  Logical topologies ⚫ Define how the media is accessed by the hosts; for example token-passing and broadcast are considered logical topologies 20 Physical Topologies 21 Bus Topology  A bus topology uses a single backbone cable that is terminated at both ends. All the hosts connect directly to this backbone. 22 Star Topology  A star topology connects all cables to a central point. 23 Extended Star Topology  An extended star topology links individual stars together by connecting the hubs or switches. 24 Ring Topology  A ring topology connects one host to the next and the last host to the first. This creates a physical ring of cable. 25 Hierarchical Topology  A hierarchical topology is similar to an extended star. However, instead of linking the hubs or switches together, the system is linked to a computer that controls the traffic on the topology. 26 Full-Mesh and Partial-Mesh Topologies  A mesh topology is implemented to provide as much protection as possible from interruption of service. For example, a nuclear power plant might use a mesh topology in the networked control systems. As seen in the graphic, each host has its own connections to all other hosts. Although the Internet has multiple paths to any one location, it does not adopt the full mesh topology. 27 END! 28