port

When a computer enables network applications, there is a very critical concept, the computer port.

The role of the port is to distinguish different applications (or processes) on the computer and realize end-to-end data transmission.

In short, to achieve communication between different computers, ports must be opened (at least one).

Port view under Windows

Cmd command netstat -ano lists all ports (occupancy of open ports)

netstat -aon|findstr "52008" View the situation of a specific port (an, ano and aon are no different)

tasklist|findstr "4000" View the process with PID 4000　

PID-process information can be viewed in the Task Manager > Processes tab.　

taskkill /f/t/im Tencentdl.exe ends the process

Configure outbound and inbound security policies to open or block ports by changing the firewall that comes with Windows

Reference (right-click to copy the link, manually open in a new window)

IIS PUT Scanner

Inline scanning of JavaScript code

Scan (link to be added)

Control the port opening function by configuring security group rules in the Alibaba Cloud console

Alibaba Cloud Manual Reference (Off-site link, copy the link by yourself and manually open it in a new window)

An important principle of port opening is to open as few ports as possible. Do not open ports that are not needed. Open ports as far as possible to the specified host or range, and close ports as soon as possible when they are not needed.
Port setting: open port 80 is written as 80/80, open 21 and 22 are written as 21/22, that is, it must be written in interval form.

Windows features

QQ remote connection operation

Other powerful remote control software such as PCAnyWhere, RealVNC, etc.

xshell and xftp are very powerful remote control software, xshell is used for command line control and xftp is used for file transfer.

Download these two softwares on the official website, they are under the same official website , and they are free, and then install them. Installation and Configuration Connection Reference
After installation, you need to configure the connection. xshell needs to use the account name and password of the server host, which is set when purchasing the server space to select the operating system or re-selecting the system settings. xftp requires the ftp account name and password, which is generated by the server itself. You can view the ftp and mysql accounts and passwords by entering the command cat account.log in xshell. Open xftp from xshell does not require xftp to enter the account password to connect, you can use it directly.
Before configuring the connection, you need to configure the security group rules of the server host in the Alibaba Cloud console. You need to open ports 21 and 22 in the inbound direction to the local IP. The local IP can be obtained by entering the IP in the browser.
After installing wordpress, you need to open the ftp 21 port to any IP for online installation of the plugin.