traceroute packet

Summary In the XMPP communication process, Asmack provides the packet component is iq,message,presence three kinds: IQ is used for query messages for message passing presence for state interaction they are all packet subclasses, The essence is the XML format used to encapsulate messages into responses for data exchange, which has good scalability. Brief introduction We take the Open source project Androi

Reading directory Wireshark Introduction Wireshark cannot do Wireshark vs fiddler Other similar tools Who will use Wireshark? Wireshark starts packet capture Wireshark window Introduction Wireshark display Filtering Save Filter Filter expression Packet List Pane) Packet details pane) Wireshark and corresponding OSI Layer-7 Model Specific content of

DHCP principles and packet formatsDynamic Host Configuration Protocol (DHCP) is a Protocol designed by IETF to achieve automatic IP Configuration, it can automatically assign IP addresses, subnet masks, default gateways, DNS Server IP addresses, and other TCP/IP parameters to the client. Understanding the DHCP process can help us eliminate problems related to the DHCP service. DHCP is an application based on the UDP layer (that is to say, only UDP pac

For general users, it is difficult to crack the neighbor's wireless LAN password. Of course, you can also find specific methods and steps by searching. I am also a beginner. Here are my articles. If you are interested, take a look.The following methods are all tested on the XP platform:.You must note in advance that the prerequisite for cracking isYou must have a NIC that is supported by the airodump software., The support Nic can be checked online (http://www.wildpackets.com/support/downloads/d

These two days to see csdn some of the socket sticky packet, socket buffer settings, found that they are not very clear, so check the data to understand the record: One. Two simple concept long connection with short connection:1. Long connection Client side and server to establish a communication connection, the connection is established to open, and then send and receive messages. 2. Short connection The client side communicates with server every tim

for the TCP-based development of the communication program, there is a very important problem to solve, that is, packet and unpacking. I. Why TCP-based communication programs require packets and unpacking. TCP is a "flow" protocol, the so-called flow, is a string of data without bounds. You can think of the river water, is connected into a piece, in the meantime there is no dividing line. However, the general communication program development needs to

I don't know how to say it. In short, the boat, from the mouth, I can not see HUANGFA and impoverished! I'm not going to say anything except cursing!Prior to BBR, there are two kinds of congestion control algorithms, based on packet loss and delay-based, regardless of which is based on detection, in other words, packet loss based on packet loss as a means to find

Packet Capture analysis tool-tcpdump Tcpdump (dump the traffic on a network) is a more practical tool for analyzing data packets in Unix, it supports filtering at the network layer, protocol, host, network or port, and provides logical statements such as and, or, not, and boolean expressions for packet header matching, in Linux, you can use yum to install yum if it is not installed. However, you need the fo

AAC raw code stream can not play directly, generally need to be encapsulated into ADTS format to use again, the blogger in Android with MEDIACODEC encoded AAC is RAW format, In order to save as. AAC format, you need to increase the ADTS header so that it can be played directly via VLC or Windows Media player. Now the online collection of information and code summed up, in preparation for their future reference, but also to share with the needs of colleagues. Source code from: Http://stackoverflo

2nd chapter, using User Space command iptables implement packet filtering 2.1 Related knowledge of TCP/IP 2.1.1 Establish a TCP connection (implemented with 3 handshake) If server A and client B communicate. (1) b->; A. When b wants to communicate with a, B first sends a SYN-tagged packet to a, telling a to request a connection. There is no other way to establish a connection until a receives a SYN

Next I will introduce a very practical method based on the characteristics of network viruses scanning network addresses: Use the packet capture tool to find the virus source. Are you a network administrator? Have you ever experienced a sudden decline in network performance, failure to provide network services, slow server access, or even access, the network switch port indicator lights are flashing like crazy, the router at the network exit is alrea

Dynamic Host Configuration Protocol (DHCP) is a protocol designed by IETF to achieve automatic IP configuration, it can automatically assign IP addresses, subnet masks, default gateways, DNS Server IP addresses, and other TCP/IP parameters to the client. Understanding the DHCP process can help us eliminate problems related to the DHCP service. DHCP is an application based on the UDP layer (that is to say, only UDP packets can be viewed during the Snort detection process). DHCP uses UDP to carry

connection requires a "three-time handshake":First handshake: The client sends a SYN packet (SYN=J) to the server and enters the Syn_send state, waiting for the server to confirm;(That is, make a connection request packet: "I want to send you data, OK?" ”）Second handshake: The server receives the SYN packet, it must confirm the customer's SYN (ACK=J+1), and also

Compared with WINSOCK1, Winsock2 most obvious is to support the raw socket socket type, using raw socket, can set the network card into promiscuous mode, in this mode, we can receive IP packets on the network, of course, including the destination is not the local IP packet,Through the original socket, we can also more freely control the various protocols under Windows, and can control the network underlying transmission mechanism. In the example of th

In the last lecture, we learned how to get the appropriate information, this one will let us write a program Chiang every packet printed through the adapter.The function that opens the device is Pcap_open (). function prototypes arepcap_t* pcap_open (const char* source,int snaplen,int flags,int read_timeout,struct pcap_rmtauth *auth,char * errbuf); 'Pcap_rmatauth{int type.Char *username;;/ /zero-terminated string containing the username that have to i

There are three scenarios when a packet passes through a firewall:1. Local-Targeted packagesWhen a packet enters the firewall, if the destination address is native, the order in which the firewall is checked is as follows:If a packet is discarded at one step, no subsequent checks are performed Steps Table Chain Description

the rule, Determined by Target:A. Continue to match the next ruleB. Make some changes to the packetC. Jump to another chain (that is, start to match each rule on the chain from that chain sequentially)D. Return the chain that raised the jump (that is, the next rule that continues to match the chain before the jump)E. Dropping a packetF. Receiving packets (i.e. no further matching, direct return)G. LoggingH .... .The entire Iptables framework executes the following process:The loop 1:static brea

Linux Network firewall NetFilter: is a frame of the kernel: framework IPTABLES: Data packet filtering: Nat mangle and other rule generation tools Network knowledge: IP packet header NB Sp TCP headers NBSP;NBSP;NBSP;HDR Len Header First ministerial The bytes given must be multiplied by landscape 32/8 = 4 bytes typeof service (service type) service type total length (total length) Total messa

Actually, for the tcpdump program, you can even say that this program is actually a customer experience, because not only can he analyze the packet flow direction, but the internal content of the packet can also be "audible". If the information you use is clear, on the router, it may have been heard by others! Awesome! So, let's get to know this experience! (Authorization: This tcpdump must use the root ide

ScenarioIf you need to use UDP to transmit large data, such as 10 m images, this breaks through the design principles of UDP. UDP is designed based on "datax", that is, it assumes that each packet you send can be contained in a single package. In addition, the maximum length of UDP data packets is limited by the basic network protocol. The maximum theoretical length of UDP data packets is 65535 bytes, which contains 8 bytes of data headers and 65527