Structure of an ip address composed of Ethernet frames

The 64-bit pre-sync code (reamble) and start frame delimiter (start frame delimiter) at the beginning of the structure of an ip address ). The pre-sync code is used to ensure that the data exchange between the sender and the receiver is the same as the upstream signal. The sender repeatedly sends 1 and 0 signals in 56 bits. The receiving end receives the signal and prepares to read the sent signal. After the pre-sync code ends, it indicates that the 8-bit (10101011) starting frame is ranked. The first Separator of a frame is followed by the address and other headers. The mac address of the receiving end and the sending end is followed by the first Separator of the frame. It is accepted only when the mac address of the acceptor is its own mac address. Otherwise, the frame is deleted. The mac address of the receiving end and the sending end is followed by a 16-bit type field (type filed ). The Type field stores the type code of the Upper-layer protocol for transmitting data in an Ethernet frame. This code is defined by the rfc1700 of the specified Ethernet protocol, such as www.2cto.com 800 ip806 arp8035 reverse arp809b appletalk8137-8138 novell814c snmp
A maximum of 12000 bytes of Ethernet packets can be stored. Ethernet is the protocol for the physical layer and data link layer. The data transmitted by an Ethernet frame is a packet defined by the network layer. If you want to use the ip network protocol, ip packets are stored in Ethernet packets. The end of the frame is the error verification and Correction Code for checking data errors. Crc redundancy check is often used.
IP address A: 0 ~ 127 0.0.0 ~ 201710000255b: 128.0 ~ 191.255 0.0 ~ 255.255C: 192.0.0 ~ 255.255.255 0 ~ 255 the ip datagram ip address of www.2cto.com is transmitted by means of the Internet function. When the router that passes through the route relay the ip datagram, the ip datagram is temporarily removed from the Ethernet packet, then, the router re-creates an Ethernet packet. The ip address of the computer resume of the sender. Ip datagram stores the information necessary for sending ip datagram, such as the ip address of the receiving end.
Establish an Ethernet frame. The Ethernet packet stores the ip datagram set up in 1. At this time, the communication parties are in the same Ethernet, and the frame will be delivered directly by referring to the route. Use the Ethernet function to send Ethernet frames to the communication line. Send the Ethernet frame to the receiver using CSMA/CD technology. The receiving end Computer extracts the ip datagram from the Ethernet frame message. The ip datagram consists of the front part of the IP datagram, where the ip version ipv4 is stored as 4. The next IHL (internet header length) is a character, that is, a 32-bit unit, it stores the length of the header from version start to end. The shortest case is that there is no option. In this case, IHL is 5. the server type field indicates the quality required by the sending end when the ip datagram is transmitted. Table 1.11 represents the composition of service type fields. The 8-bit datagram length field refers to the length of the ip datagram in bytes. It identifies the field and the data block offset. Tcp and udp use the port concept to distinguish programs on computers.
The field "sorce port" of the TCP Message segment is the port number of the sender and client program, destinaion port, and the port number of the receiver segment. "sequence no" indicates the value of a certain byte in which the data of the message segment is located in all data blocks. acknoledgment number the receiving end uses control bits to indicate the status of tcp communication for the long reserved extension of the data block value received by the sending end www.2cto.com data offset header. "Urg indicates emergency Data Pointer valid ack indicates Missing Persons valid psh transmission force function rts continuous request reset syn request sequential number synchronous processing fin indicates sending ends" window size, one checksum error check of the amount of data that can be sent using urgent pointer to insert signals and other emergency data end position options, padding options and fill