1. 20 LAN Hardware Overview Version A.01 H3065S Module 2 Slides

2. © 1999 Hewlett-Packard Co. H3065S A.01 21 LAN Hardware Components a67319 A LAN is composed of several hardware components: servers and workstations LAN interface cards transmission media other network devices - repeaters - hubs - bridges - switches - routers

3. © 1999 Hewlett-Packard Co. H3065S A.01 22 Transmission Media a67320 Twisted Pair Coaxial Fiber Optic Woven metal shield Plastic insulating jacket Nonconducting insulator Central copper conduit Plastic insulating jacket Central copper conduit Glass or plastic fiber insulator cable Photodiode receiver Terminator Light-emitting diode or laser transmitter

4. © 1999 Hewlett-Packard Co. H3065S A.01 23 LAN Topologies a67321 T T Bus Ring File Server Star Hub

5. © 1999 Hewlett-Packard Co. H3065S A.01 24 LAN Access Methods a67322 Originating Workstation Token Passing Recognizes destination address Copies message Sends token back to source Seizes token Changes status to frame Transmits data Receives token back Removes message Issues new token Token CSMA/CD

6. © 1999 Hewlett-Packard Co. H3065S A.01 25 IEEE 802.3 Standard a67323 Mainframe Workstation Packet travels in both directions Network Packet Terminator

7. © 1999 Hewlett-Packard Co. H3065S A.01 26 IEEE 802.5 Standard a67324 Token circulates

8. © 1999 Hewlett-Packard Co. H3065S A.01 27 FDDI Standard a67325 Dual Attachment Station (DAS) Dual Attachment Concentrator (DAC) Primary Ring Secondary Ring Single Attachment Stations (SAS) FDDI Dual Ring Router Backbone

9. © 1999 Hewlett-Packard Co. H3065S A.01 28 Repeaters and Terminators a67326 R Repeater Terminator Signal on wires Terminators Repeaters Repeaters extend the network by propagating signal. Repeaters Pass all traffic through without error checking. Repeaters Pass errors and collisions through. Terminators Terminators are required at each end of a bus LAN segment. Terminators absorb the signal on the wire so it does not reflect back. R

10. © 1999 Hewlett-Packard Co. H3065S A.01 29 Hubs a67327 Hubs Network signal is automatically repeated across every port Works like a multi-port repeater Physical star topology; but is implemented as a logical bus topology Can easily add/remove nodes without disrupting network Errors and collisions are passed through Usually uses twisted pair instead of coax for workstation connections Hub

11. © 1999 Hewlett-Packard Co. H3065S A.01 30 Bridges and Switches a67328 Switch Bridge Bridges Bridges contain two or more separate interface cards and connect multiple segments on the same network. Bridges forward frames based on the destination MAC address. Bridges use “store and forward” to ensure no errors are passed onto another segment. Bridges do not pass errors or collisions through to another segment. Switches Switches work similar to a multiport bridge in that they connect multiple “collision domains”. Switches can maintain simultaneous connections; multiple active circuits allow data to be forwarded in parallel. Address Table Card 1 Card 2 080009-1A23C4 080009-234ABC 0060B0-7EF226 080009-23EF45 080009-987654 080009-1A23C4 080009-23EF45 Card 2 Card 1 0060B0-7EF226 080009-234ABC080009-987654

12. © 1999 Hewlett-Packard Co. H3065S A.01 31 Routers and Gateways a67329 Network 128.1.0.0 Network 192.1.1.0 Network 15.0.0.0 Network 128.2.0.0 Router Routers Routers connect different networks and different LAN types. Routers forward packets based on destination IP addresses. Routers exchange routing information and use this information to build route tables. Each router has a minimum of two LAN cards; each LAN card has its own IP address. Routers do not forward broadcast packets; broadcast packets are dropped. Gateways Gateways used primarily to implement wide area networks (WANs). Gateway

13. © 1999 Hewlett-Packard Co. H3065S A.01 32 Pulling It All Together a67330 B R B Router Gateway Router R R G G Bridge Repeater Bridge Switch Hub Dual FDDI Ring Token Ring