tcp udp port scan

. Pass the PRC_XXXX error code to the control input function of the protocol.The 3.internet PCB protocol (TCP and UDP) maps a prc_xxx error code to a UNIX errno value, which is returned to the process.8.udp_usrreq functionMany operations call the Protocol's user request function, and one of the five write functions is invoked on a UDP socket to call

data. Either party establishes a socket and can send data using sendto, or it can receive data with Recvfrom. There is no concern about whether the other party exists or not, and whether the data is sent. It is characterized by a faster communication speed. We all know that TCP is going through three handshakes, and UDP is not.Depending on the above, the UDP and

Superscan as Administrator;2) Add IP address range;3) Start scanning;4) View the scan results;5) View the computer port information;This result includes information such as the scanned computer's IP address, host name, and the open port in the computer.2. Scan target computer portHackers generally prefer to use the sc

TCP/IP, UDP, HTTP, socket inside and out The network is divided from bottom to top: corresponding Physical Layer Data Link Layer Network layer (IP protocol) Transport layer (TCP protocol) Session Layer Application layer and Presentation layer (HTTP protocol) The socket is the encapsulation and application of the TCP/

speed. We all know that TCP is going through three handshakes, and UDP is not.Depending on the above, the UDP and TCP programming steps are somewhat different, as follows: Tcp:The general steps for the server side of TCP programming are:1, create a socket, with a function s

on system resources (more TCP and less UDP)3. UDPProgramSimple Structure4. Stream mode and datagram Mode5. TCP ensures data correctness, UDP may cause packet loss, TCP ensures data order, and UDP does not guaranteeIn addition, le

not guarantee In addition, let's talk about their differences based on the situation of the GPRS network:1. TCP transmission has a certain latency, which is about 1600 ms (provided by mobile devices). The UDP response speed is slightly faster.2. TCP Header StructureSource Port 16-bit16-bit Target Port32-bit serial nu

of UDP that affect the design and implementation of servers that use this ProtocolClient IP address and port numberThe UDP server must save the source IP address and the source port number from the customer datagram, which allows an interactive UDP server to handle multiple

speed. This is the main reason why streaming media is not high quality. On the contrary, UDP has been implemented among some trojan horse viruses. hackers develop scripts and trojans to run over UDP in order to mask their activities. UDP packets are also used in DoS (Denial of Service) attacks. it is important to know the difference between

transfer control information for IP. It is used primarily to provide path information about the destination address. ICMP ' Redirect ' information informs the host of more accurate paths to other systems, while ' unreachable ' information indicates a problem with the path. In addition, if the path is not available, ICMP can cause the TCP connection to terminate ' gracefully '. Ping is the most commonly used ICMP based service. 5.

' field, enter the port number '3688/udp '. 6. select TCP or UDP, depending on the Protocol required for port 3688/UDP.Download Free Software: Windows 7/Vista/xphow to scan a PC/network for simple-push-s

control information for the IP. It is primarily used to provide information about the path to the destination address. ICMP ' Redirect ' information informs the host of a more accurate path to other systems, while the ' unreachable ' message indicates a problem with the path. Additionally, if the path is not available, ICMP can cause the TCP connection to ' gracefully ' terminate. Ping is the most commonly used ICMP-based service. 5.

delivery services for TCP, UDP, sctp, and ICMPv6. TCP transmission control protocol. TCP is a connection-oriented protocol that provides a reliable full-duplex byte stream for user processes. TCP socket is a stream socket. TCP

it. 3. ClientB-1 send UDP packets to ClientA-1 (202.103.142.29:5000), of course, this package will be discarded when it arrives at Nat-a, which is not critical, because this UDP packet is sent only to let Nat-b Remember the purpose of this communication: port number, the next time the source of this address and port d

First, the reference note, this blog post for reference to the following1.BLUETZAR,TCP/IP Four-layer model,http://www.cnblogs.com/BlueTzar/articles/811160.html2. Ye Jianfeng, random talk about TCP,http://www.cnblogs.com/yjf512/p/5909031.html3.bizhu,tcp and UDP differences (RPM),http://www.cnblogs.com/bizhu/archive/2012

model and the corresponding relationship between the protocolNetwork layer------------IP (interconnection protocol between networks)Transport Layer------------TCP (Transmission Control Protocol), UDP (User datagram protocols)Application tier------------Telnet (standard protocol and primary method for Internet Telnet service), FTP (Text Transfer Protocol), HTTP (Hypertext Transfer Protocol)3. IP address and

UDP and TCP use port numbers to send and receive data simultaneously for multiple applications. Data is sent out through the source port and received through the target port. Some network applications can only use reserved or registered static ports, while others can use unr

is packet oriented. The packet sent by the sender's UDP to the application is delivered to the IP layer after the header is added. Without splitting or merging, the boundary of these packets is retained. Therefore, the application needs to select the appropriate packet size.We often use the "ping" command to test whether the TCP/IP communication between the two hosts is normal. In fact, the "ping" command

second conversation. host a sends another packet to confirm that host B's request is synchronized: "I will send it now, let's proceed !", This is the third dialogue. The purpose of the three "dialogs" is to synchronize the transmission and receipt of data packets. After the three "dialogs", host a formally sends data to host B. TCP protocol can be appliedProgramA reliable communication connection is provided, so that the byte stream sent by a compu

TCP Connection Scan:Client and server establish a TCP connection to do a three-time handshake, if a successful three-time handshake, the port is open;TCP SYN Scan (also known as semi-open scan or stealth