First, TCP
Commonly used port scanning methods are the following three: 1.connect scanning
We know that the common TCP socket implementation process is
The more essential connection and end process is the following:
From the above two figures we
Introduction and backgroundTCP programming is one of the most interesting aspects of network programming. In Ubuntu, I like to use. NET Core for TCP programming and use native Ubuntu scripts to communicate with a TCP server. Before, I was. The NET
Before scanning:Nmap Scan Report for 192.168.0.39Host is up (0.00029s latency).All scanned ports on 192.168.0.39 is filteredMAC Address:00:0c:29:ef:80:d6 (VMware)After opening:Nmap Scan Report for 192.168.0.39Host is up (0.00038s latency).Not shown:9
SSH port forwarding
Through the introduction in this article, you can learn how to apply the SSH port forwarding mechanism to solve some problems in daily work/life. Learn to use port forwarding in a non-secure environment to encrypt network
-Frequently used commands detailed
Basic Commands
$ tcpdump//default crawl all packets of the first NIC interface
$ tcpdump–i ens33//crawl NIC ENS33 packet
$ tcpdump host 47.95.224.4// Listen for host 47.95.224.4 receive all packets sent
$tcpdump
Comments: Ubuntu11.04 the default is UFW (ufw is short for uncomplicated firewall, which is not complex firewall. You still need to go to iptables for complicated settings). Interface operations are supported. Run the ufw command on the command line
One of the simplest operations:sudo UFW version firewall versions: UFW 0.29-4ubuntu1 Copyright 2008-2009 Canonical Ltd.Ubuntu system has UFW installed by default.1. Installationsudo apt-get install UFW2. Enablesudo UFW enablesudo ufw default
Web site Environment
LAMP. What is LAMP? It is Linux + Apache + MySQL + php/perl abbreviation, is a concise, strong, widely supported site environment. At home there seems to be a lot of people recommend to change A (Apache) to N (Nginx), but I do
Under Ubuntu Open port seems to have two main methods, one is Ubuntu comes with the firewall, one is iptables, here we mainly use iptables. The system version for this article is ubuntu14.04 and ubuntu16.04
Installing IptablesIn general, when
Refs
Http://askubuntu.com/questions/293356/how-to-open-a-particular-port-in-ubuntu
Run this on the commandline; It should solve Issue:sudo iptables-a input-m conntrack--ctstate new,related,established-j ACCEPT
To do a specific port:
sudo
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