This document provides an overview of Ethernet networking including: 1. Ethernet uses layers 1 and 2 of the OSI model and the Network Access layer of the TCP/IP model. It evolved from early LAN technologies and uses frames, MAC addressing, and CSMA/CD. 2. Switches avoid collisions by forwarding frames only to destination ports, improving performance over hubs. Higher bandwidth standards like Fast Ethernet and Gigabit Ethernet require full-duplex links without collisions. 3. Ethernet addressing uses MAC addresses to identify devices locally and IP addresses to route between networks. ARP resolves IP addresses to MAC addresses to allow communication between hosts.

1. Ethernet CCNA Exploration Semester 1 Chapter 9

9. Hubs and switches Switch forwards frames only to the destination once the address is known. Hub forwards frames through all ports except incoming port.

14. Ethernet Frame Packet Packet Trailer Frame header Packet from Network layer is encapsulated Packet Data Frame Check Seq. 46-1500 4 Field size in bytes. Preamble and SFD are not counted in frame size. Frame is 64-1518 (later 1522) bytes. Preamble Destination address Start of frame delimiter Source address Length /type 7 1 6 6 2

26. Listen for signals Are there signals on the cable? Yes .

27. Wait if there are signals Wait until there are no more signals

28. Listen for signals Are there signals on the cable now? No .

29. Put signals on cable Put my signals on the cable.

30. Listen for collisions: no No collision. All is well. My message was sent.

31. Listen for collisions: yes There is a collision. Stop sending signals. Send jamming signal. My message is lost.

32. Listen again No signals now. Wait for a random length of time. Send message again.

52. Labs & Activities * If no previous Packet Tracer experience, else strongly recommended Type Detail PT 1.2.4 Mandatory* Lab 1.3.1 Mandatory PT 1.3.2 Mandatory Lab 1.3.3 Review carefully