© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 1 Understanding Network devices Internetworking Fundamentals Instructor: Abdirahman I. Abdi

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 2 Content Network Devices:  Hub  Bridge  Switch  Router

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 3 Hub Problem with hub: it has only: 1 Collision Domain 1 Broadcast Domain It doesn’t Matter how many hubs inter-linked together !!

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 4 Bridge Splits network Learns MAC Addresses Bridges Famous in the mid 80s and early 90s Bridges are slow A B C D 2 1

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 5 Switch Cisco C3560 Switch 24 ports - Each port is a Collision Domain - Supports Full Duplex Communication - Learns MAC Addresses done by Hardware chip (ASIC) Application Specific Integrated Circuitry rather than software

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 6 Switch CAM (Content Accessible Memory)

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 7 Router - Router’s basic function is to connect two networks. For example, from a private corporate network to the ISP’s network. - Routers work at the bottom 3 Layers, Physical, Data and Network layer. Sometimes routers work on layer 4 Transport layer to provide reliable end-to-end delivery -A router can determine: - Destination address - Priority level of each packet transmitted - Example Video, Audio and etc - The least-cost route - Minimum delay route and many more.

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 8