tcp udp port scan

Document directory I. Software Packages I. Software Packages 1. nmap-5.21.tar.bz2 Ii. Installation Steps 1. tar xvf nmap-5.21.tar.bz2 2. cd nmap-5.21 3../configure 4. make 5. su root 6. make install 7. nmap www.sina.com Starting Nmap 5.21 (http://nmap.org) at 2010-07-15 CST Nmap scan report for www.sina.com (202.108.33.89) Host is up (0.0042 s latency ). Hostname www.sina.com resolves to 16 IPs. Only scanned 202.108.33.89 Not shown: 999 filtered po

TCP, UDP programming exercisesTCP☆ Upload text fileReads a local text file, sends the data to the server side, and stores the data. After the storage is complete, give the client a hint.first, the idea of solving problemsClient: (1) Create socket object----with server ip+ port number(2) read the contents of the file(3) through the socket to send the content to th

192.168.1.1TCP Connect () scan (ST) If the SYN scan is not selected, the TCP connect () scanning is the default scan mode. Unlike the TCP SYN Scan, the TCP connect ()

active only scans the port for an instant, and only the services used at that time are likely to be detected. 3-port scanning is a generalized attack behavior, for the last licensed machine, generally can not be implemented. The advantages of passive Passive only listens to the network, does not become the network attack, it runs for a long time, can detect the change of the server within a long interval.

also be able to send and receive files, including both text and binaryFiles (e.g., images). Note that all communication between clients must is sent via your server.Clients communicate with your server via TCP or UDP. For TCP, clients connect via a specific TCPPort number (i.e., the listener port); This

service135/tcp Open msrpc136/tcp closed profile137/tcp closed netbios-ns139/tcp open Netbios-ssnmac Add Ress:5c:f3:fc:e4:81:40 (IBM) Nmap done:1 IP address (1 host up) scanned in 0.14 seconds[[email protected] scanport]#-SP Specifies that the scan mode is ping (does not

. TCP Message structure:The header of the TCP segment has a fixed portion of the first 20 bytes, and the following 4n bytes are the fields that are added as needed and are the complete TCP message structure:20-byte fixed part, each field function description: Source and Destination ports : 2 bytes each, write the source

Plot? Tcp / ip? Sixth chapter? TCP vs. UDP? Note 6.1 The role of the transport layer?The transport layer must indicate this specific program, in order to achieve this function, use the port number of such an identification code. Depending on the port number, it is possible t

Because the UDP protocol is non-connection-oriented, the UDP port detection cannot depend on the connection establishment process as the TCP port detection (TCP protocol commands such as telnet cannot be used ), this also makes

ARP part IP ICMP UDP part TCP Section 1. UDP IntroductionUDP is a simple datagram-oriented transport layer protocol. Each output operation of a process generates a UDP datagram and assembles it into an IP datagram to be sent. This is different from the stream-oriented character protocol, such as

implemented in the operating system kernel. Figure 1 TCP/IP protocols The following describes the Differences Between TCP and UDP in the transport layer. 1. User Datagram Protocol (UDP) User Data Protocol (UDP) is a connectionless transport layer Protocol in the OSI refere

process generates a UDP datagram and assembles it into an IP datagram to be sent.. (Unreliable and connectionless) UDP Header The size is 8 bytes. Included Fields: 16-bit source port number and 16-bit destination port number16-bit UDP length, 16-bit

the SR packet from Ssrc_n to send this report. 2.4. RTP Session Process When an application establishes a RTP session, the application determines a pair of destination transport addresses. Destination transport address consists of a network address and a pair of ports, with two ports: one to the RTP packet, one to RTCP packet, so that the RTP/RTCP data can be sent correctly.RTP data is sent to even UDP ports, and the corresponding control signal RTCP

About portsCommunication between any two hosts on the internet is from one end to the other, also known as end-to-end communication.What is a port?Modern operating systems are equipped with many applications, information to my computer how do I know this message is passed to my QQ application? My QQ program is responding but my MSN did not respond to it?The reason: My system has a number of port numbers, ea

TCP/IP Note 3. Transport Layer (1) -- UDP, TCP 1. Transport Layer 1.1 two Protocols: TCP and UDP. (1) TCP: provides a reliable data transmission service. TCP is connection oriented and

the UDP protocol. Datagram (Datagrampacket ):Construct a datagram that can contain the data to be sent and the acceptor address. UDP (Datagramsocket ):Build the sender and receiver that implements the UDP function to send and receive data packets. UDP network programming method: Write the receiver program:① Call mon

Enterprise Port Scan Policy 1, the purpose of port scanning for the computer system located in the network, a port is a potential communication channel, that is, an intrusion channel. Port scanning of the target computer can get a lot of useful information to discover the s

tcpdump-I eth1 pppoes-W/tmp/xxx. the CAP is separated by a size of 100 MB to save the file. If the size of the CAP is greater than 10000 MB, an additional file-C 10000 m is opened to capture packets and then exit-C background to capture packets. The exit of the console will not affect the file: nohup tcpdump-I eth1 port 110-W/tmp/xxx. cap You can use ethereal or Wireshark to open the captured file. 2. Linux NMAP scanning and sniffing tools Map, o

the application layer has confirmed the fact that it has arrived. Non-connection-oriented protocols cannot detect duplicate and out-of-order packets. Standard Terminology uses "unreliable" to describe UDP. In modern networks, UDP is not easy to cause transmission failures, but you cannot say it is reliable. Ii. TCP WorkflowNow let's take a look at the various f

TCP handshake, the process of exchanging between the client and the server that controls the message. The client, which is the initiator of the TCP connection, sends a SYN message to the server, which is listening on a TCP port. The server receives and sends a SYN-ACK message, which is the receiving client again using