packet catcher

I. Overview: 1. ICMP agrees to report errors on the host or route and provides relevant exceptions. ICMP is a standard protocol for the Internet, but ICMP is not a high-level protocol, but an IP layer protocol. Generally, ICMP packets are used by the IP layer or higher-level protocols (TCP or UDP. Some ICMP messages return error messages to the user process. 2. The ICMP packet is used as the data of the IP layer datagram, And the header of the datagr

During the packet capture module, we have seen some data packet interception methods as follows:1. Use the pcap software package. The Linux version of pcap is the Libpcap function library, and the corresponding function library in Windows is Winpcap. The protocol analysis software etheral is implemented based on this software package (but not limited.2. Use the original socket. For example, the UDP proxy se

Recently in the socket transmission, encountered packet loss problem, troubled for a long time, saw this article, the original address: http://suwish.com/html/java-tcp-socket-stream-packet-split.html is good, now much easier. In other words, the official "empty track" animation schedule of falcom and the broken people are displayed. I mean it is really unacceptable. Of course, we can't handle this either. W

Traditional Campus Network Services lacks effective E2E locating methods, resulting in long fault diagnosis time and difficulty, making it difficult to meet user requirements. Network Performance Fault Diagnosis and quality evaluation are very important. Currently, many research groups and standards organizations are engaged in technical research and standard formulation. IETF has developed RFC5357 (A Two-Way Active Measurement Protocol) and RFC4656 (A One-way Active Measurement Protocol (OWAMP

I. Overview: 1. ICMP agrees to report errors on the host or route and provides relevant exceptions. ICMP is a standard protocol for the Internet, but ICMP is not a high-level protocol, but an IP layer protocol. Generally, ICMP packets are used by the IP layer or higher-level protocols (TCP or UDP. Some ICMP messages return error messages to the user process. 2. The ICMP packet is used as the data of the IP layer datagram, And the header of the datagr

I. Overview: 1. ICMP agrees to report errors on the host or route and provides relevant exceptions. ICMP is a standard protocol for the Internet, but ICMP is not a high-level protocol, but an IP layer protocol. Generally, ICMP packets are used by the IP layer or higher-level protocols (TCP or UDP. Some ICMP messages return error messages to the user process. 2. The ICMP packet is used as the data of the IP layer datagram, And the header of the datagr

Code protocol structure definition---------------------------------------# Pragma pack (1) // enters the byte alignment ModeTypedef struct framheader_t{// The data frame header captured by pcapByte dstmac [6]; // target MAC addressByte srcmac [6]; // source MAC addressWord frametype; // Frame Type} Framheader_t;Typedef struct ipheader_t{// Ip address data HeaderByte ver_hlen; // version + Header LengthByte TOS; // service typeWord totallen; // The total length.Word ID; // IDWord flag_segment; //

I have answered a few questions I have submitted in blog posts and csdn. I found a solution code later: Now we need to use C # As a WebServices interface for C ++ to call.WebServices has been defined (only one of the simplest web methods is described here, and security verification is omitted ):Void process (byte [] request, out byte [] Response) (this parameter cannot be changed)Parameter description: the type of the received parameter byte []. The output parameter byte []. Based on the receive

Evaluation of several network packet capture tools and several toolsEvaluation of several packet capture tools by Bin Laden's brotherRecently, I wrote a CMD remote control that says I want to do something on the server.We all know that soft false positives, especially those reported by black software, are normal.For this reason, some people may not install software. Basically, they rely on themselves to ana

I. Overview: 1. ICMP agrees to report errors on the host or route and provides relevant exceptions. ICMP is a standard protocol for the Internet, but ICMP is not a high-level protocol, but an IP layer protocol. Generally, ICMP packets are used by the IP layer or higher-level protocols (TCP or UDP. Some ICMP messages return error messages to the user process. 2. The ICMP packet is used as the data of the IP layer datagram, And the header of the datagr

I. Overview: 1. ICMP allows the host or route to report errors and provide relevant exceptions. ICMP is a standard protocol for the Internet, but ICMP is not a high-level protocol, but an IP layer protocol. Generally, ICMP packets are used by the IP layer or higher-level protocols (TCP or UDP. Some ICMP messages return error messages to the user process. 2. The ICMP packet is used as the data of the IP layer datagram, And the header of the datagram i

Ps:tcpdump is a tool for intercepting network groupings and outputting grouped content, which is simply the packet capture tool. With its powerful capabilities and flexible interception strategy, tcpdump is the preferred tool for network analysis and troubleshooting in Linux systems.Tcpdump provides source code, exposes interfaces, and is therefore highly extensible, and is a useful tool for network maintenance and intruders. Tcpdump exists in the bas

1. Packet forwarding rate of the switch The packet forwarding rate of the switch marks the size of the switch forwarding packet capability. Unit General bit BPS (packet per second), the packet forwarding rate for general switches ranged from dozens of kpps to hundreds of MP

# Description ------------- maindump. sh (the main program for packet capturing) uses the endless loop detection every one minute to allow the program to continuously capture packets. considering that the packet capturing results may be too large, the analysis tool cannot open the analysis, therefore, the size of each packet is limited to about 100 MB. the

TCP requires ACK, but for efficiency, instead of waiting for ACK every time a piece of data is sent, it tries its best to use the window mechanism to accumulate ack sending, of course, in some special circumstances, Ack still needs to be sent immediately, for example, when unordered data is received, although the receiving end can temporarily store unordered data packets, however, the receiver must send an ACK with the expected serial number in order to the sender. In addition, the receiver must

Keywords TCP IP Packet Structure Detailed network protocol In general, network programming we only need to call some of the encapsulated functions or components can do most of the work, but some special circumstances, it requires in-depth understanding Network packet structure, and protocol analysis. such as: network monitoring, troubleshooting, etc... IP packet

"Package" (Packet) is a data unit in TCP/IP protocol communication transmission and is generally referred to as "packet". Some people say that the LAN transmission is not "frame" (frames)? Yes, but the TCP/IP protocol is working on the third layer of the OSI model (the network layer), the fourth layer (the Transport layer), and the frame is working on the second layer (data link layer). The contents of the

Ext: 1190000008836467This article describes how a data packet is transferred from a NIC to a process in the hands of a Linux system in a single step.If the English is not a problem, it is strongly recommended to read the following two articles in the reference, which is described in more detail.This article discusses only the physical network card of Ethernet, does not involve virtual devices, and takes the receiving process of a UDP

This is an article I wrote before in the green corps. It was originally written by myself. I learned from a t00ls article and made improvements. The name of my account in the green corps is also leisureforest.There is no doubt about the authenticity. ThanksDatabase packet capture alternative backupAddress http://www.bkjia.com/(used only to replace the target website, not this site)Database packet capture al

Wireshark and TcpDump packet capture Analysis and Comparison Common packet capture analysis tools include Microsoft's Network Monitor and Message Analyzer, Sniff, WSExplorer, SpyNet, iptools, WinNetCap, WinSock Expert, Wireshark, and linux tcpdump. Today, we conducted an experimental test to compare and analyze two of them. Other users can use Baidu Google to test yiha ^_^. 1. Wireshark and tcpdump Introduc