CCNA Study Notes 2 --- Ethernet

CCNA Study Notes 2 --- Ethernet
Ethernet ◆ type: 1, EthernetII; 2, 100 standard Ethernet (10 Mbps) Fast Ethernet (1000 Mbps 10 Gbps 40 Gbps, using CSMA/CD access control, all are in line with 802.3 ◆ L2 network Classification 1, point-to-point: WAN network serial port 2, multi-point} ---- Ethernet broadcast} ---- Frame Relay does not support broadcast ◆ collision over Ethernet, when the two nodes transmit data at the same time, the frames sent from the two devices will collide and encounter each other on the physical media, and the data will be damaged. A csma/CD conflict domain (collision domain) is the network range of broadcast frame transmission in a broadcast domain that supports shared media. Generally, a vro is used to set the border, because the router does not forward multicast data. ◆ Maximum packet length and minimum packet length of Ethernet: 1518 bytes; minimum packet length of layer-3 data: 1500 bytes (MTU): 64byte Ethernet frame structure: Ethernet frame forward guide code: physical layer concept, it is used to indicate that the start 10101010 of the frame indicates that this is a layer-2 data type. If the value is 0800, it indicates that the IP address is equal to that of the two ends. If the value is 802.3, the Front Guide code is 1010111. MAC address: OUI: the unique identifier of the organization (purchased by different vendors) is 48th bits 1-> broadcast 0-> unicast 47th bits 1 has no global significance, only Local Use ◎ full-duplex Ethernet half-duplex Ethernet currently only wireless ◎ ethernet cable order 568B 1 2 568A 3 6 ◆ target IP address request MAC