header length

One day, when I was restricted by many secular rules and could not do what many normal people could do, I suddenly felt: people should not have come to this world! Since we fell into the ground, we have been destined to suffer a lot in our life...

In general, we only need to call encapsulated functions or components for network programming. However, in some special cases, it is necessary to thoroughly understand the structure of network data packets and protocol analysis. Such as network

Basic protocols running on Ethernet 1. Introduction A network listening tool was compiled some time ago. To analyze captured data packets, you must be familiar with various network protocols. I am suffering from the fact that there are few articles

TCP/IP network protocol BASICS (1) Introduction This article is a basic knowledge of TCP/IP protocol. It focuses on the content and functions of TCP/IP protocol clusters and the basic knowledge related to TCP, UDP, and IP network protocols. Content

[Network layer] network layer Overview 1. What are the differences between the two service virtual circuits and the datagram service provided by the network layer? Virtual circuit datagram connection must be established. Do not use the destination

TCP and IP protocol-header structure (figure)IP protocolThe IP Protocol (Internet Protocol) is a network layer Protocol used on the Internet. TCP, UDP, ICMP, and IGMP data are all sent in the IP data format. The IP protocol provides unreliable and

I 've been reading IP, TCP checksum for half a day online. The following is the simplest command, no data 45 0 0 34 4D C5 40 0 72 6 20 E1 D3 93 4 CC C0 A8 1 16 4E 23 6 8F 36 CA 45 A3 EC 73 cb fb 80 10 1E E8 D0 2A 0 0 1 1 8 A 15 f ac fe 0 A1 EF the

Explanation of TCP/UDP data packets (1): IP data packet structure 1. Graph IP data packets consist of four bytes per line (32 bits) from the header and Data) the first part contains at least 20 bytes (5 rows), and the option part is optional.

Access Control List (i)? TCP and UDP protocolThere are two main transport layer protocols for TCP/IP protocol family: TCP (transmission, Transmission Control Protocol) and UDP (user Datagram Protocol, subscriber Data hold protocol).? TCP ProtocolTCP

We use the Internet every day, how is it implemented?The core of the Internet is a series of protocols that collectively "Internet Protocol" Internet Protocol suite.1: Overview1.1 Five-layer modelThe realization of the Internet, divided into several

　The TCP creation process and the link dismantling process are created automatically by the TCP/IP protocol stack relative to the socket developer. Therefore, the developer does not need to control this process. But it is quite helpful to understand

1, network commonly used conceptsThe web is the soul of application and the source of data for all applications. Away from the network, our application is backwater, the network is the media of data interaction, we get the data on the server through

1. Datagram (Datagram) format:2. Length Field(1) Header Length field,Hlen,4 bits In 4-byte (or 32bits) units Value: 5~15 (that is, the first length is bytes) (2) Total Length field, sumlength, bits In byte units

Two ways to define a computer network:1. Generally, the dispersed multiple computers, terminals and external equipment with communication lines to communicate with each other, and the computer hardware, software and data resources can be used

This digest is from Linux kernel ip.h, thanks to the open source GNUstruct IP {#if __byte_order = = __little_endian unsigned int ip_hl:4;/* header length */ unsigned int ip_v:4;/* version */#endif#if __byte_order = = __big_endian unsigned

This article excerpt from: http://www.kuqin.com/shuoit/20141008/342511.html 七、一个 SummaryFirst, make a summary of the previous content.We already know that network communication is the exchange of data packets. Computer A sends a packet to Computer B,

The DFS server that uploaded files in batches yesterdayProgram, And then share it in the first place. Of course, the program is messy, because some of the information I debug is left in it. It is original, and some comments are not deleted, I think

1. TCP protocol (Transmission Control Protocol) is end-to-end reliable and connection-oriented protocol. The processing object is called a TCP segment (segment) and is a stream-based protocol. 2. Unlike UDP, TCP has two caches for sending and

The previous article analyzed the overall concept of the Internet, from bottom to top, the design of each layer of protocol.This is from the designer's point of view, today I would like to switch to the user's perspective, to see how users from top

Maximum Transmission Unit (MTU) refers to the Maximum data packet size (in bytes) that can be passed over a layer of a communication protocol ). The maximum transmission unit parameter is usually related to the communication interface (network