What is a reverse IP lookup

Finding the IP address associated with the host name (domain name) and finding the host name (domain name) associated with the IP address is called a reverse lookup. [Recommended reading: What does IP mean]

First of all, it looks for the corresponding host name (domain name) IP address, that is, an address on the Internet. For example, if you want to see the homepage of the URL "http://www.php.cn/" (host name), the corresponding IP address is the Internet address of the website server where the URL is stored. Instead of numbers, it is easier for us to remember the hostname (http://www.php.cn/) as a string.

For example, in the log of the Web server, the IP address as the connection source (for example, 61.191.56.8) is recorded. This reverse can find the host name (domain name). The string of the host name or the domain name can be was found.

In addition, it can be achieved to a certain extent that the origin connection source obtains the IP address and the original IP address through behavioral accuracy, and then subtracts it again from the host name that has passed the reverse check (domain name).

This is because the acquisition of the domain name and IP address is performed separately, and the administrator can be separate, but there is no rule that must match the correspondence between the forward and reverse lookups.

For example, suppose you are building a web server using a line provided by your Internet service provider. The hostname and domain name of the web server are arbitrary strings, and the hostname can be looked up from the reverse of the IP address provided by the program. In this case, the correspondence between forward lookup and reverse lookup does not match. However, building a web server by reversing the IP address of the server fails.

How to forward lookup by hostname and reverse IP address

First, run "Command Prompt" on Windows or "Terminal" on Mac OS .

Enter "cmd" in the run that appears and click "OK". Click the button to display the command prompt, which is displayed as follows:

The above is a complete introduction to what a reverse IP address is, if you want to learn more about operation and maintenance knowledge , please pay attention to php Chinese website.

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