linux packet sniffer

C language-based LIBPCAP implementation of a packet capture program processThe overall architecture of the Pcap-based sniffer program is as follows: (1) First decide which interface to use to start sniffing. In Linux, this could be eth0, while in the BSD system it could be xl1 and so on. We can also use a string to define the device, or use the interface name pro

Data Packet Classification and scheduling-another explanation of Linux TC-linuxtcIf you understand the Linux TC framework from the perspective of layered recursion, it is easy to classify queues into class queues and class-free queues. In this perspective, the status of a queue is equal to that of a queue. But in fact, there is a hierarchical relationship between

servers and nodes on other networks, not only to detect attacks from outside the network, at the same time, it also has a strong preventive effect on internal malicious damages. The security of the monitoring firewall has exceeded the packet filter type and the proxy server type firewall, but its implementation cost is high. Based on the comprehensive consideration of system cost and security technical cost, users can choose to use some monitoring te

package, filled the entire buffer, so received C,In the user's time on-chip users collected all the data in the buffer.C, the next data in droves, causing the buffer has been in full state, so the subsequent reception can be filled with user buffer.D, receive the E at the end of the entire buffer, and then receive the closure of the packageTo verify the above inference, test 6 was performed.Test 7 verifies the sending and receiving situation at the time of the fast send, proves that send sends

Tcpdump is a Sniffer tool, which is actually a packet capture tool on the network. It can also analyze captured packets. Generally, the system is installed by default. Tcpdump command description: tcpdump uses the command line method. the command format is: tcpdump [-adeflnNOpqStvx] [-c quantity] [-F file name] [-I network interface] [- TcpdumpIt is an Sniffer to

Transferred from: http://cizixs.com/2018/01/13/linux-udp-packet-drop-debug?hmsr=toutiao.ioutm_medium=toutiao.ioutm_ Source=toutiao.ioRecent work encountered a server application UDP packet loss, in the process of reviewing a lot of information, summed up this article, for more people to refer to.Before we get started, we'll use a graph to explain the process of r

Implement router and packet filtering firewall in Linux Router and Firewall]Vro is a widely used device between IP segments. There are many ready-made products on the market. In applications, we often connect routers across the WAN and lan. Most router products are designed based on this need. However, with the expansion of the user's IP network, we need a router that can address multiple Ethernet networks

210.27.48.2 or 210.27.48.3, run the following command: (when parentheses are applied in the command line, be sure # Tcpdump host 210.27.48.1 and/(210.27.48.2 or 210.27.48.3 /) C if you want to obtain the IP package for all hosts except 210.27.48.1 and 210.27.48.2, run the following command: # Tcpdump ip host 210.27.48.1 and! 210.27.48.2 D. to obtain the telnet packet received or sent by the host 210.27.48.1, run the following command: # Tcpdump tcp p

Install Cisco Packet Tracer in Linux What is Cisco Packet tracer? Cisco Packet Tracer is a powerful network simulation tool used for Cisco authentication training. It provides us with a good interface view for various routers and network devices. These simulation devices have many options. Like physical machines, we c

Linux Network Programming-original socket instance: Packet Analysis of MAC header, linux Network Programming We learned through "Linux Network Programming-original socket programming" that we can get the data packets at the link layer through the original socket and recvfrom ().What we receiveWhat is the length of link

The 1th chapter, router-based packet filtering firewall General concepts of 1.1 packet filtering firewalls 1.1.1 What is a packet filter firewall A packet filtering firewall is a software that looks at the header of the packet that flows through it, thus determining the fate

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

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 mainten

1. tcpdump is a good tool for tracking the system behavior of processes in the local machine. in the debugging of network problems, tcpdump is an indispensable tool, like most excellent linux tools, it features simplicity and power. By default, tcpdump does not capture packets for internal communication on the local machine. According to the network Association I,Tcpdump Strace is a good tool for tracking system behavior calls of processes in the loca

Compile and install the NIC Driver in linux (NIC packet loss)-Linux Enterprise Application-Linux server application information. The following is a detailed description. Install and compile the NIC Driver In the past two days, I found that the packet loss of a server is very

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 mainten

Structure and Principle Analysis of the packet capture module based on Linux-Linux Enterprise Application-Linux server application information. The following is a detailed description. This section discusses the structural features of the monitoring layer data packet capture

1 Introduction to Analog delay transmission Netem and Tc:netem are a network emulation module provided by the Linux kernel version 2.6 and above. This function module can be used to simulate complex Internet transmission performance in a well performing LAN, such as low bandwidth, transmission delay, packet loss, and so on. Many distributions Linux that use 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

This article comes mainly from the manual of the man Packet Linux comes in:Http://man7.org/linux/man-pages/man7/packet.7.htmlUsually used in the inet socket provides a 7-layer grasp of the ability to grab the data is directly TCP or UDP payload, do not care about L3 and L4 header information.Packet socket provides the