What is an Ethernet Frame made of?
Preamble - 56 alterna.ng ones and zeros used for synchroniza.on (101010...)
SFD - Start Frame Delimiter - designates the end of the preamble (10101011)
Destination MAC Address - Ethernet MAC address of the des.na.on device.
Source MAC Address - Ethernet MAC address of the source device.
EtherType - Describes the data contained the payload.
Payload - Layer 3 and higher data.
FCS - Frame Check Sequence - CRC checksum of the frame.
• CS - Carrier Sense
• Is there a carrier? Is anyone communicating?
• MA - Multiple Access
• More than one device on the network
• CD - Collision Detect
• Collision - Two stations talking at once • Identify when data gets garbled