hardware sniffer

network is a small frame (frame) of the transmission of the frames are composed of several parts, different parts to perform different functions. (for example, the first 12 bytes of Ethernet hold the source and destination addresses, which tell the network: where and where the data is coming from.) Other parts of the Ethernet frame hold the actual user data, the TCP/IP header, or the IPX message prime).Frames are molded by a specific network driver and then sent to the network cable via the NIC

introducing the concept of SNI er, we must first introduce some basic concepts of LAN devices.Data is transmitted in a small frame unit on the network. frames are composed of several parts and different parts perform different functions. Frames are driven by a specific network Program The software is molded, and then sent to the network card through the network card, through the network cable to reach their target machine, at the end of the target machine to execute the opposite process. The et

header content, this mode is usually called the "hybrid" mode.In a common network environment, account and password information are transmitted in plaintext over Ethernet. Once an intruder obtains the root permission of one of the hosts, and put it in a hybrid mode to eavesdrop network data, which may intrude into all computers in the network.In a word, sniffer is a hacker and tool used for eavesdropping.Ii. Working Principles of snifferGenerally, al

. The data captured in the network is called sniffing ). Ethernet is now the most widely used computer connection method. The Ethernet protocol sends packet information to all hosts in the same loop. The data packet header contains the correct address of the target host. Generally, only the host with this address will accept this data package. If a host can receive all data packets and ignore the packet header content, this mode is usually called the "hybrid" mode. In a common network environmen

From -- http://blog.csdn.net/zhangnn5/article/details/6810347 Reading this articleArticleBefore that, I suppose you already know the TCP/IP protocol, ARP protocol, What Is sniffer, and other basic network knowledge.In a General Lan, there are usually two access methods, one is hub access (The Hub here refers to the general hub ), one is direct access from a vswitch (the vswitch here is a relatively advanced vswitch, which is not included in the old-

small Frame unit on the network. frames are composed of several parts, and different parts perform different functions. (For example, the first 12 bytes of Ethernet are the Source and Destination addresses, which tell the network the source and destination of the data. Other parts of the Ethernet frame store the actual user data, TCP/IP packet header, or IPX packet header ). The frame is formed by a specific network driver and then sent to the network cable through the NIC. The opposite process

to call Winpcap and wrote sniffer in the console. ~ _*Download path: Software/Network/Winpcap/(including the latest version, stable version, and Development Documentation) 3. Network Associates sniffer portableVersion: v4.7.5 SP4Updated on: 2004-05-20Introduction: as the main product of Nai, Sniffer produced by Nai is expensive.

BKJIA recommendation: Sniffer security technology from entry to entry Learning the concept and principles of Sniffer is the foundation of Sniffer security technology. How should we get started with the knowledge of Sniffer security technology? Next let's introduce it to you one by one. 1. What is

PHP-made port sniffer--you can specify the website and port and return the sniff results. function Http_request ($server, $port) { $data = ""; $query = "head/http/1.0"; $fp = Fsockopen ($server, $port); if ($fp) { Fputs ($FP, $query. " Rnn "); while (!feof ($fp)) { $data. = Fread ($fp, 1000); } Fclose ($FP); } return $data; } ?> if ($action = = "Query") { $data = Http_request ($server, $port); echo "Connected to $server on port $port. ";echo "Outp

parsing.The last three lines of code are specific applications where we use pcapy for data capture.pcap = pcapy.open_live(dev, 1500, 0, 100)Open_live method The first parameter is the device to be opened, the second parameter is the size of the capture packet, whether the third parameter turns on promiscuous mode, the fourth parameter is the delay time to wait for the packet, and the method returns a Pcapy object.pcap.setfilter(filter)Call the SetFilter method to set the filter.pcap.loop(0, han

○ Collation This article was written one year ago and was not completed for some reason. Today, I sorted out shadowstar's home and accidentally found this unfinished article. Although it was a year ago, it is still not out of date and should be helpful to anyone who wants to know sniffer. My father said that everything should start and end. Today is the Dragon Boat Festival. I would like to send a message to my loved ones who are far away from each ot

and the damage of network equipment. You can use the Host List feature in sniffer to see which machines in the network have the most traffic, and combine the matrix to see which machine data flow is abnormal. Thus, we can judge the specific fault points of the network in the shortest time. 2, Network attacks: with the continuous development of the network, hacker technology has attracted a lot of network enthusiasts. So, some of the primary hackers,

). Therefore, Sniffer is often used for "special" purposes. Sniffer application The Sniffer tool has many different functions and designs. Some can only analyze one protocol, while others may be able to analyze several hundred protocols. Generally, most sniffing devices can analyze at least the following protocols: standard Ethernet, TCP/IP, IPX, and DECNet, ofte

check the alarm log to see if the network is running normally. Iv. Application of Sniffer in network maintenance-solving network transmission quality problems Sniffer's Application in Internet cafes mainly uses its traffic analysis and viewing functions to solve network transmission quality problems in Internet cafes. 1. broadcast storm: broadcast storm is the most common network fault in Internet cafes. The emergence of a network broadcast storm is

and non-classic communication. SSH was later developed into F-SSH, providing high-level, military-level encryption of the communication process. It provides the most universal encryption for network communication through TCP/IP. If a site uses a F-SSH, the user name and password are no longer important. Currently, no one has broken through this encryption method. Even Sniffer, the collected information will no longer be valuable. For more information

communication. SSH was later developed into F-SSH, providing high-level, military-level encryption of the communication process. It provides the most universal encryption for network communication through TCP/IP. If a site uses a F-SSH, the user name and password are no longer important. Currently, no one has broken through this encryption method. Even sniffer, the collected information will no longer be valuable. For more information, see ssh-rela

. Software sniffing has the advantages of being cheap and easy to use. The disadvantage is that it is often unable to capture all the transmitted data (such as fragments) on the network, so it may not be able to fully understand network faults and running conditions. A hardware sniffer is usually called a protocol analyzer. Its advantage lies in the fact that software s